Back to main article

Landsat-8 Imagery in the period 2021

References

• December 28, 2021: The saguaro cactus (Carnegiea gigantea), with its spiny, branching arms, is an icon of the American West. It is also the largest cactus in the United States, growing up to 60 feet (18 meters) tall. The saguaro only grows in the Sonoran Desert, with its habitat range limited to southern Arizona, southeast California, and western Sonora, Mexico. Although not listed as threatened or endangered, the saguaro is protected by state laws against harvesting or destruction. ¹⁾

​

​​

- Under the right conditions, saguaro cacti can live to be 150 to 200 years old. The extremely slow-growing saguaro is particularly sensitive to temperature range and water abundance, and highly variable or extreme weather can stress the plants and limit reproduction. In Saguaro National Park, scientists have long monitored the climate. Over the past century, winter minimum temperatures in the area have risen 10 to 15º Fahrenheit (6 to 8ºC). Researchers have also recorded less rain falling in the winter, but more in the summer, when the cacti are thought to take up most of their water. When rain is abundant, a fully hydrated saguaro can weigh 3,200 to 4,800 pounds (1,500 to 2,200 kg). However, due to drought over the past few decades, fewer young saguaros are surviving in the park.

​

​​

- Ecologists are looking for new tools to help monitor plant populations, and some are training computers to identify plants in remotely sensed images, either aerial or satellite. Some recent studies have used such machine learning to survey and map populations of saguaro, which cast shadows that can be identified in imagery. The researchers suggest such tools could be especially useful for monitoring remote, arid environments.

• December 27, 2021: A survey team on a remote island in Arctic Canada came across a grisly sight in the summer of 2016. Caribou carcasses, dozens of them, lay strewn across the tundra of Prince Charles Island, just north of the Arctic Circle in Nunavut. Based on the condition of the carcasses and the decomposition of internal organs, death was estimated to have occurred at least several weeks prior to the team’s arrival, perhaps in late winter. While some animals died lying down, others appeared to have simply collapsed. ²⁾

- A half-century earlier and more than 4,200 miles (6,800 km) west, a similar scene confronted biologists on a remote speck of land in the Bering Sea. Forty-two reindeer were found foraging among the skeletal remains of a reindeer herd on St. Matthew Island that only three years earlier had numbered 6,000 animals.

​

​​

- While caribou and reindeer are the same species (Rangifer tarandus), they are not the same animal. Caribou, which live in North America, are migratory and travel in large herds between breeding grounds. Reindeer inhabit Europe and Asia and have adapted to domestication. They can be used for pulling sleighs and can be milked like cows and goats. (Reindeer cheese is reported to be mild and creamy.)

- One key attribute caribou and reindeer share is that they are herbivores that feed on lichens and plants. In late fall and early spring, they use their sharp hooves to break through the icy crust on northern lands to reach this food source. While the animals are adapted to efficiently managing their energy reserves over the long Arctic winter, timing is everything. And at both Prince Charles Island and St. Matthew Island, time ran out for the herds.

​

​​

- Unusually harsh winter weather also was the culprit on St. Matthew Island. Scientists reanalyzing meteorological data found that the winter of 1963–1964 was one of the harshest ever recorded in the Bering Sea islands. The reindeer endured storms with hurricane-force gusts, wind chills as low as -71.5° Fahrenheit (-57.5° Celsius), and a record amount of snow. As at Prince Charles Island, the hard crust on the snowpack made it difficult, if not impossible, for the huge reindeer herd to access vital nutrients. For the 6,000 reindeer, there simply was not enough food available when it was most needed. By 1966, only 42 survivors remained.

- Through the use of remotely sensed data, scientists were able to close the cold case of the mysterious deaths of caribou in Canada and reindeer in the Bering Sea islands occurring a half-century apart. The data told the tale.

• December 21, 2021: Before Cumbre Vieja split open on September 19, 2021, the western flank of La Palma was dotted with houses, roads, pools, and crops. After slow-moving lava flows bulldozed their way down the small volcanic peak in the Canary Islands for months, parts of the island now look more like a moonscape than a tropical paradise. ³⁾

​

​​

- The slow-moving lava flows have caused tremendous amounts of damage to homes, infrastructure, and farmland. Some areas that were not directly overrun by lava have been blanketed with ash. According to a mid-December update from the Copernicus Emergency Management Service, the eruption has destroyed at least 1,600 buildings. Lava has consumed at least 12 km² of land, including at least 4 km² of crops. Initial estimates say that the eruption has caused at least 550 to 700 million euros in damages.

- After three months of vigorous lava flows and explosive activity, there are signs that the eruption may be ending. On December 14, geologists with the Canary Islands Volcanology Institute (INVOLCAN) noticed a sharp decline in seismic activity; explosive activity, sulfur dioxide emissions, and lava flows also waned. While activity could pick up again, ten days of inactivity would prompt local scientific authorities to declare the eruption over, according to Canarian Weekly.

​

​​

• December 15, 2021: During the time of the pharaohs, the fertile soils along the Nile River likely supported a civilization of roughly 3 million people. Now there are 30 times that number of people living in Egypt, with 95 percent of them clustered in towns and cities in the Nile’s floodplain. Much of the growth has come in recent decades, with the Egyptian population soaring from 45 million in the 1980s to more than 100 million now. ⁴⁾

- Just 4 percent of Egypt’s land is suitable for agriculture, and that number is shrinking quickly due to a wave of urban and suburban development accompanying the population growth. “It’s not an exaggeration to say that this is a crisis,” said Nasem Badreldin, a digital agronomist at the University of Manitoba. “Satellite data shows us that Egypt is losing about 2 percent of its arable land per decade due to urbanization, and the process is accelerating. If this continues, Egypt will face serious food security problems.”

​

​​

- While the conversion of farmland to human settlements here has occurred for decades, multiple researchers observed sharp increases in the practice after the “Arab Spring” roiled the political and economic climate in Egypt starting in 2011. In recent years, Egyptian authorities have vowed to put an end to unlicensed building on farmland, though it remains a difficult practice to stamp out.

- Urbanization is not the only process putting pressure on Egypt’s farmland. Sea level rise of 1.6 mm per year has contributed to problems with saltwater intrusion and the salinization of farmland in Egypt, particularly in the fringes of the delta southwest of Alexandria. About 15 percent of Egypt’s most fertile farmland has already been damaged by sea level rise and saltwater intrusion, according to the UN Food and Agriculture Organization. While global warming is responsible for about half of the sea level rise affecting the Nile Delta, the sinking of the land (subsidence) is responsible for the other half. Natural compaction, as well as the extraction of groundwater and oil, contribute to subsidence.

​

​​

- While that project has not come to full fruition yet, large swaths of desert have been converted to farmland in recent decades. The pair of images below shows new farmland and the emergence of several new towns along the Cairo Highway. A mixture of center-pivot irrigation and drip irrigation—fed by groundwater pumps—makes farming in this area possible, explained Badreldin. While small-scale sustenance farming is common in the main part of the delta, most of the growers on the desert edge raise grains, fruits, and vegetables for export abroad.

- “It is certainly possible to establish new farmland from the desert by tapping groundwater resources, but it’s a difficult, resource-intensive, and expensive process,” said Badreldin. “The poor soils and the intensive resources needed to farm in the western desert are a poor replacement for the richer, more fertile soils in the delta.”

- Boston University researchers Curtis Woodcock and Kelsee Bratley have analyzed decades of Landsat observations as part of a Boston University effort to track how the availability of farmland in the delta is changing over time. “We certainly see expansion into the desert, but there’s nuance to this story,” said Woodcock. “After being farmed for a time, we also see a significant amount of that new farmland being decommissioned and reverting to desert.”

• December 9, 2021: A low-pressure system called a “Kona low” developed northwest of Hawai’i in the first week of December 2021, dropping snow on the peaks of Mauna Kea and Mauna Loa. The storm also brought high winds, intense rainfall, and flash flooding, along with reports of landslides, downed trees, and power outages. Some roads and schools were closed, and Hawai’i Governor David Ige declared a state of emergency. ⁵⁾

​

​​

​

​​

- While blizzard conditions are rare in Hawai’i, snow is not uncommon on the two tallest volcanoes in the island chain. Snow is often associated with a Kona low, which occurs when winds that typically blow out of the northeast shift and begin to blow from the southwest, over the leeward or “Kona” side of the islands. As the air, laden with moisture from the tropical Pacific, is forced up by the mountainous topography, the moisture precipitates as heavy rain and snow. Kona storms are common between October and April.

• December 6, 2021: At roughly 325 km², the Ebro Delta on the northeastern coast of Spain is one of the largest wetlands along the Mediterranean Sea coast. It is an important habitat for wildlife, including flamingos and birds using the wetlands as a stopover on migratory journeys. The site in southern Catalonia has been designated a UNESCO Biosphere Reserve. ⁶⁾

- The 50-kilometer-long coastline features two sand spits: El Fangar on the north shore and La Banya on the south. These appendages are the remnants of the river's previous deltas, which were reworked when the river changed course over the past few thousand years.

​

​​

​

​​

- The delta, which is home to 62,000 people, has also been greatly modified by human use. In the past 150 years, wetlands have been converted into fields of rice, which now cover up to 80 percent of the delta. To supply water for irrigation and to generate hydroelectric power, more than 187 dams have been built on Ebro River and its tributaries—development that trapped most of the sediment supply in Spain’s largest river in reservoirs and behind dams. Erosion and land subsidence followed downstream.

- Today, the shape and form of the delta is no longer controlled by the river, but by sea waves. And with sea-level rise and more frequent and intense storms, those waves are getting bigger, leading to further shoreline retreat. In January 2020, the narrow sandbar that connects the southern spit to the main delta was flooded by storm Gloria, along with 3,000 hectares of rice fields. Storms also exacerbate the shrinking and loss of dune fields on the beaches.

- The Ebro Delta illustrates the hard choices to come for communities facing rising seas—try to hold back the ocean or manage the retreat.

- The Spanish government recently announced a plan to buy coastal land to create a buffer zone. If the plan is adopted, the purchase would constitute the largest land buyout in Europe so far due to climate change. But it is opposed by many of the delta's inhabitants, some of whom instead favor beach nourishment, pumping, and seawalls to protect the coast. Some farmers are experimenting with strains of rice that can better withstand saltwater intrusion.

• December 4, 2021: Mount Michael, an active stratovolcano in the South Sandwich Islands, is viewed more often by penguins than by people. It is located on Saunders Island, about 1,600 km (1,000) miles from Antarctica and 2,400 km (1,500 miles) from South America, and there are no permanent human residents nearby. For satellites looking down from space, the mountain is usually obscured by clouds. Still, the nearly 1,000-meter-tall volcano frequently finds a way to put on a show. ⁷⁾

​

​​

- The feature is possibly a type of cloud known as a volcano track. These “tracks” occur when passing clouds interact with the gases and particles from a volcano. The extra particles from the volcano produce more and smaller cloud droplets, which make the cloud appear brighter. “As the cloud moves over the volcano, the imprint of those smaller droplets stay in the cloud, resembling a stream or a track of different texture when seen from above,” said NASA atmospheric scientist Santiago Gassó, who spotted the feature and routinely hunts for volcano tracks in satellite images.

- Volcano tracks can be difficult to discern in natural-color images. This image is false color, composed with a combination of shortwave infrared and blue light (OLI bands 7-6-2) to help distinguish the track from the rest of the cloud deck. Also notice the striking lenticular cloud. Unrelated to the volcanic activity, these clouds can develop at the crest of atmospheric waves that form when wind encounters a topographic barrier and is forced up.

- Volcano tracks are a useful tool for scientists trying to spot cases of less intense volcanic activity. Such activity—the simple “puffs” of water vapor, particles, and gases—is common, but often goes unreported because the emissions usually stay below (or within) the clouds. By studying the clouds around these volcanic puffs, scientists have been gaining insight into how clouds form and evolve.

- There is also the chance that the plume from Mount Michael on November 7 rose above the cloud deck, meaning the feature would be a typical volcanic plume, and not a volcano track. “The Landsat image has so much detail. I can see several shadows suggesting that what I called a volcano track is actually a plume positioned immediately above the cloud deck—low enough to cast a small shadow,” Gassó said. “But at the same time, it is unusual to have such an organized plume above the cloud deck without dissipating or thinning out more readily.”

- Without lidar data to measure the feature’s height, it is not possible to know if the feature is volcano track or a plume. Either way, Gassó notes: “There is some beauty in it, right? In that same way, it triggers curiosity to find more.”

• December 2, 2021: After a planning and construction process that spanned decades, a flood control system in Venice is now regularly protecting the low-lying city from high water. Satellites caught a rare glimpse of the system in action during a high-water storm event in November 2021. ⁸⁾

- On the afternoon of November 3, 2021, the flood gates were raised as a storm brewed in the Adriatic Sea. At the time, forecasters warned that water levels might rise 140 cm above normal when high tide peaked and strong sirocco winds battered the Venetian coast. Water at that level is enough to flood 60 percent of the city, including the iconic St. Mark’s Square, the lowest part of the city.

​

​​

- The system, named MOSE (Modulo Sperimentale Elettromeccanico) — includes 78 submerged barrier gates that are normally tucked into the seafloor. When weather forecasts show damaging floods (above 130 cm or 4.3 feet) are imminent, operators rotate the gates upward to form a temporary seawall that rises above the water surface. As shown by the Landsat-8 and Sentinel-2 images on this page, the seawall prevents water from the Adriatic Sea from flowing through key inlets into or out of the shallow lagoon that surrounds Venice.

- “It is quite rare to get Landsat or Sentinel imagery showing the barriers closed because they are only activated and above the surface during storms—when there is usually too much cloud cover to see them from above,” explained Luca Zaggia, a coastal oceanographer at Padua’s Institute of Geosciences and Earth Resources of the Italian National Research Council (CNR). “It is even more unusual for satellites to capture images of sediment stirred up by the movement of the barriers because this phase lasts less than 30 minutes.”

​

​​

- Landsat-8 passes over the area once every 8 days; one of the Sentinel-2 satellites make observations once every 2 to 3 days. Zaggia is part of a research team from Venice’s Institute of Marine Science that is investigating how the operation of MOSE could affect the movement and abundance of sediment around the lagoon.

- Activating the flood gates proved successful in this case. While high tide water levels rose above 130 cm in the Adriatic Sea, they reached just 83 cm in Venice, enough to prevent major flooding. MOSE has been used several times in recent years as engineers test it and work toward making it fully operational by 2022. The floodgates were activated five times in 2021 and 20 times the previous winter. In 2019, before the system was available for use, more than 25 high-water events swamped Venice, including a November flood that proved to be the second worst on record.

- Though MOSE has prevented several high-tide floods, sometimes high water has eluded system operators due to inaccurate weather and water height forecasts. For instance, much of Venice flooded in December 2020 after forecasts underestimated the maximum height of high tide by 5 cm — enough to prevent operators from elevating the barriers in time.

- Rising global sea levels might affect the level of protection the system provides in coming decades. With relative sea levels rising by roughly 0.25 cm per year, the frequency of high-water events in Venice has already increased in recent decades, going from two per decade during the first half of the 20th Century to more than 40 per decade now. “In the best case emissions scenarios (RCP-2.6), the system should work well until the end of this century,” said Federica Braga, a remote sensing expert at Venice’s Institute of Marine Sciences, though he cautioned the system could begin to be overwhelmed sooner under worst case emissions and sea level rise scenarios.

- Some researchers have calculated that the system will need to be closed for 3 weeks per year by the end of this century under a low-emissions scenario and for at least two months by 2080 under a high-emissions scenario. “A reduction in the number of water exchanges could trigger other problems in the long term even if the system mitigates the worst of the flooding,” said Zaggia. “For instance, it could change the sediment budget and negatively affect salt marshes or the water quality of the lagoon.”

• December 1, 2021: Some of the highest diurnal tides in the world—nearly 14 meters (46 feet)—have been recorded in the Sea of Okhotsk. In the Russian Far East, narrow bays funnel and amplify the incoming tides, making it a prime location for tidal power generation. ⁹⁾

​

​​

- The currents around the Shantar Islands are heavily influenced by the strong tides and by freshwater discharge from rivers draining into Uda Bay. The waters here are frozen for much of the year. When the sea ice melts and freshwater snowmelt swells the Uda River, plumes of low-salinity water can reach far offshore.

- As the strong tides and currents flow through straits in the Shantar Islands, they encounter rocky outcrops, headlands, capes, and small islands that disrupt the laminar flow. This can create chains of spiral eddies that rotate in alternate directions as they form. These chains are known as vortex streets or von Kármán vortices. The physical processes that create the vortices were first described in 1912 by Theodore von Kármán, a Hungarian-American physicist and a co-founder of NASA's Jet Propulsion Laboratory. In the Shantar Islands, vortices in the chain propagate mainly to the east at low tide and to the west at high tide.

• November 29, 2021: Greenland’s glaciers function like bulldozers, grinding away and pulverizing rocks along the land surface as they creep through valleys toward coastal waters. The process produces a fine-grained powder of silt and clay called glacial flour that accumulates underneath and around glaciers. This powder often accumulates in deltas and in meltwater lakes and streams that form along the edges of these slow-moving rivers of ice. Since the particles are so fine, they are slow to sink and often remain suspended in water longer than other types of sediment. ¹⁰⁾

​

​​

- The presence of silt can sharply change the appearance of water. When sunlight hits silt-rich water, particles absorb the shortest wavelengths: the purples and indigos. Water absorbs the longer wavelengths: reds, oranges, and yellows. That leaves mainly blues and greens that get scattered back to our eyes, often giving silty water a striking turquoise color. Water full of glacial flour can also appear milky green or brown depending on lightning conditions and the concentration of the silt.

- Ocean currents had carried two plumes of silt about 40 km (25 miles) to the south when Landsat-8 acquired this image on November 15, 2021. However, that was not the only day when satellites captured striking images of silty plumes stretching into the Labrador Sea. On November 10, an unusually narrow sediment plume stretched more than 180 km (120 miles) to the east.

- Silty plumes coming from Frederikshåb and other glaciers in Greenland are actually quite common. According to one analysis of satellite data, Greenland delivers about 8 percent of all the sediment deposited in the oceans each year even though it provides just 1 percent of the total fresh water. About 15 percent of Greenland’s glaciers—Frederikshåb among them—deliver more than 80 percent of all the sediment from the island. The researchers also found evidence that the volume of suspended sediment delivered to the ocean from glaciers in this part of Greenland has increased substantially in recent decades as the pace of retreat has quickened.

- While increased rates of ice loss in Greenland are a worrisome sign for future sea levels on Earth, some scientists think that an increasing abundance of sand and glacial flour deposited along Greenland’s coasts could have some practical uses for Greenlanders. The sediment could be collected to help relieve global shortages of sand, according to some researchers. Other scientists are looking into whether Greenland’s glacial flour could be used as a fertilizer for crops.

• November 23, 2021: There are few other places like Daintree rainforest in far north Queensland. Thought to be among the most ancient forests in the world, Daintree has many plants with lineages that scientists have traced back hundreds of millions of years to a time when several continents were joined together as Gondwana. All seven of the world’s oldest surviving fern species can still be found in Daintree, as well as 12 of the world’s 19 most primitive flowering plants. ¹¹⁾

​

​​

- Many of the species found in Daintree are exclusive to the area. For the 40 million years since Australia broke from the Gondwana, evolutionary processes have hummed along in geographic isolation, yielding unusual types of animals such as marsupials and monotremes. That long period of isolation, along with northern Queensland’s stable and mild climate and rugged topography, has resulted in remarkable biodiversity. This one ecosystem provides habitat for 65 percent of Australia’s fern species, 60 percent of its butterflies, and 50 percent of its birds.

- Among the birds is the endangered southern cassowary — a large, flightless ratite with a blue head, two red wattles, and a distinctive dinosaur-like bony casque on its head. Cassowaries, the third largest type of bird in the world, have the helpful habit of distributing and seeding at least 70 different types of trees as they forage for fallen fruit.

- In September 2021, the Queensland government returned ownership of Daintree National Park to the Eastern Kuku Yalanji, an indigenous group that has had a presence in Australia’s rainforests for at least 50,000 years. Daintree, Ngalba-bulal, Kalkajaka and the Hope Islands national parks are managed jointly by the Eastern Kuku Yalanji people and the Queensland Government since the handover.

• November 16, 2021: Since the 1960s, archaeologists have been gathering physical evidence that Norse people landed and settled for at least a few years in far northern Newfoundland, Canada, long before Columbus sailed to the Americas. At L’Anse aux Meadows, the Vikings constructed housing and workshops of timber and sod, and left behind food, tools, and bits of building material that scientists have been analyzing. But exactly when were they there? The latest answer comes from the Sun and its electromagnetic relationship to Earth. ¹²⁾

- Using clues from literature and history—such as tales of Vinland from Norse sagas—and from radiocarbon dating of wood and bone fragments, researchers previously estimated that the Vikings were frequent visitors or settlers at L’Anse aux Meadows between 970 and 1030 CE. Many researchers suggested they lived there three to ten years, with one team claiming it may have been as long as one hundred years.

​

​​

​

​​

- In a new study published in October 2021, scientists found that the Vikings were in L’Anse aux Meadows in 1021, exactly 1000 years ago. Led by scientists from the University of Groningen and Parks Canada, the team used geochemical dating techniques to analyze wood fragments and nail down the precise year the trees were cut down near the site. ¹³⁾

- Earth is regularly bombarded by radiation from space, mostly from the Sun, including benign visible light and radio waves and less benign ultraviolet light and X rays. (Much of it is absorbed, reflected, or refracted by our atmosphere.) The universe also pulses our planet with cosmic rays and other radiation, a phenomenon that creates carbon-14 when the energy collides with gases in our atmosphere. Sometimes the Sun also releases violent bursts of radiation that can make carbon-14 and beryllium.

- Such an outburst helped Michael Dee, Margot Kuitems, and colleagues pinpoint the date of Viking life in Newfoundland to 1021. Other researchers previously found evidence of an extreme space weather event in late 992 and early 993 CE; historic records from Germany, Korea, and Iceland described vivid red auroras at middle latitudes that winter. (Auroras are usually provoked by solar storms.) The event created an increase in atmospheric carbon-14 on Earth, and such increases are absorbed into the tissues of trees as they grow. By studying gnarled wood fragments from L’Anse aux Meadows, Dee and colleagues were able to spot the carbon-14 boost and then count tree rings in three separate samples. All three pieces of wood were cut from trees in 1021.

- Whether the Vikings were in Newfoundland before or after 1021 is not certain, but the evidence says they were there for at least that year, cutting trees and building things. Today you can visit remnants of their stay, along with recreations of a forge, church, and other buildings, at L’Anse aux Meadows National Historic Park, a UNESCO World Heritage Site. It is the earliest known European settlement in the Americas, and it resembles similar Norse settlements from that era found in Iceland and Greenland. Archaeologists are also investigating evidence that Native American people lived in or passed through the L’Anse aux Meadows area about 5,000 years ago before the Vikings.

• November 13, 2021: In early October 2021, the James Webb Space Telescope arrived in Kourou, French Guiana, where it is scheduled to launch from Europe's Spaceport in mid-December. Once deployed, Webb—a collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA)—will be the world's largest and most powerful space telescope. ¹⁴⁾

- Before its sea voyage, the telescope was folded for the last time at Northrop Grumman's facility in Redondo Beach, California. It was then loaded aboard the French ship MN Colibri, which sailed through the Panama Canal and up the mouth of the Kourou River, from which sediment had to be dredged to accommodate the large ship's draft.

​

​​

​

​​

- The facility's location, just 500 km north of the Equator, gives a boost to rockets launched to the east—an extra 460 m/s of speed due to Earth's rotation. The position on the northeastern coast of South America also provides clear launch trajectories to the north and east for both polar-orbiting and geostationary satellites, taking them out over the ocean and away from population centers.

- The site was also chosen for its low risk of cyclones and earthquakes. French Guiana's stable, crystalline basement rocks date back 2.2 billion years to the Paleoproterozoic Era, which also give this "overseas department" the claim to the oldest rocks in France.

- The spaceport has hosted more than 240 launches since 1990, mainly those employing Ariane, Soyuz, and Vega rockets. Notable missions include the joint ESA/Japan Aerospace Exploration Agency BepiColombo mission to orbit Mercury; ESA's Envisat Earth-observing satellite in March 2002; and four satellites in ESA's Sentinel series of Earth-observers.

- The launch of the James Webb Space Telescope in December 2021 will be the culmination of more than two decades of work by a team of 10,000 people, spanning 14 countries and 29 U.S. states. Commissioning will take six months, during which time Webb will carry out the most complicated series of deployments of any NASA mission ever.

- The immense telescope had to be folded to fit inside the fairing of the Ariane 5 spacecraft, the only rocket large enough to hold it. Once in space, the telescope's final destination is the second Lagrange Point (L2), a stable gravitational point 1.5 million kilometers from Earth where it will orbit the Sun. The trip to L2, four times the distance from the Earth to the Moon, will take a month. Upon arrival at L2, Webb will have to do "origami in reverse," as it unfolds its mirror and deploys the sunshields, said Alphonso Stewart, the Webb deployment systems lead at GSFC.

- The launch is only the beginning for the community of astronomers, astrophysicists, and cosmologists who anticipate using the telescope to resolve unanswered questions about the origins of the universe. Webb's 6.6-meter mirror has six times the collecting power of the Hubble Space Telescope, which collects light in the visible, ultraviolet, and a portion of the near-infrared spectrum. Webb will collect light in the red, and near- and mid-infrared range of the spectrum. This will allow it to see through massive clouds of gas and dust that are opaque to telescopes like Hubble, and to detect light from the early universe that has been stretched by its expansion and "red shifted" into the infrared part of the spectrum.

- Like a veritable time machine, Webb will allow scientists to look back 13.5 billion years to the first light in the universe and see how the first stars and galaxies formed and evolved over millions of years.

• November 8, 2021: Change is constant and common on Earth across geologic time. But in the icy polar regions, change has been dramatic and swift in the past few decades. One example is northwest Greenland, where quite a lot has changed in 21 years. ¹⁵⁾

​

​​

- The images show a 80-kilometer (50-mile) stretch of coastline. Like so many places around the edges of Greenland, a series of glaciers here carry ice from the island’s interior toward the coast and onto the ocean. Most of these marine-terminating glaciers are retreating. Kjer and Hayes—the two main outlet glaciers shown above—are also speeding up.

- Notice that in 2000, Kjer Glacier abutted a few rocky outcrops. These rocks helped buttress the ice and slowed its oceanward flow. Then sometime in 2012, the glacier’s floating ice shelf disintegrated. The rocks became free-standing islands, surrounded in the 2021 image by open water and a mixture of sea ice and icebergs, or mélange. Having lost contact with the rocks, the glacier’s inland ice can flow even more rapidly toward the ocean.

- According to Alex Gardner, a snow and ice scientist at NASA’s Jet Propulsion Laboratory, data from ITS_LIVE and the NASA MEaSUREs program show that one year before the ice shelf’s breakup, the glacier flowed at an average speed of 1,200 meters per year. By 2018, the glacier’s average speed was more than 4,000 meters per year.

- “Kjer is experiencing a nearly four-fold increase in ice flow due to the collapse of its floating ice shelf, likely due to melting by warmer ocean waters,” Gardner said. “This has led to increased contributions of ice to the ocean and is accelerating sea level rise.”

- In the 1970s, the Greenland Ice Sheet gained about as much ice as it lost—a balanced state that lasted until the mid 1990s, at which point ice loss sped up. Between 2002 and 2021, Greenland shed about 280 gigatons of ice per year, adding 0.8 mm (0.03 inches) per year to global sea level rise.

​

​​

• October 28, 2021: In October 2021, natural-color images from the Landsat and Terra satellites returned striking views of record-breaking backlogs of container ships idling offshore of some of America’s largest ports. Surging demand for consumer goods, labor and equipment shortages, and an array of COVID-related supply chain snarls have contributed to the backlogs. ¹⁶⁾

- Now atmospheric scientists are working with air pollution data collected by satellites to find out whether the unusual shipping activity is affecting air quality near ports. Though other industries and processes may be playing a role, a preliminary look at satellite observations of nitrogen dioxide pollution offshore of ports suggests that shipping may be contributing to an uptick in pollution.

​

​​

​

​​

- These data were collected by the Tropospheric Monitoring Instrument (TROPOMI) on the European Commission’s Copernicus Sentinel-5P satellite, built by the European Space Agency. The predecessor to TROPOMI, the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite, makes similar measurements. (Note: a recent algorithm change can artificially elevate more recent TROPOMI observations of NO₂ by 10 to 15 percent. The maps on this page have corrected for this.)

- The elevated concentrations of NO₂ near the ports appear to be at least partly a consequence of having dozens of ships waiting several days to unload their cargo. On October 21, there were 105 ships waiting for a berth at the Los Angeles and Long Beach ports, according to data from the Marine Exchange of Southern California. While ship backups are not as severe off of New York/New Jersey, those port facilities have also seen some backlogs and unusually high cargo movement in recent months.

- Since there is only enough room for roughly 60 cargo ships to drop anchor in shallow waters near the Los Angeles and Long Beach ports, the rest of the waiting ships are held in deeper waters, where they keep their main engines running and move in circles to maintain their position. Even ships that are anchored still need to run auxiliary engines to keep key systems operational. On multiple occasions in October 2021, anchored ships had to activate their main engines or move to deeper water to ride out inclement weather. All of these scenarios generate emissions of nitrogen dioxide, sulfur dioxide, fine particulate matter (PM_2.5), and other pollutants that can lead to more smog and ozone downwind in more populated areas.

- In addition to the large numbers of waiting ships, another factor that may be contributing to higher pollution levels is that all three ports are processing significantly more goods than in previous years due to surging consumer demand. The Los Angeles and Long Beach ports have seen roughly 50 percent increases in the movement in cargo in some months in 2021 compared to 2019, according to a report from the California Air Resources Board. Likewise, the port of New York/New Jersey reports record-breaking cargo volumes in 2021.

- The satellite observations of nitrogen dioxide also hint at other processes happening onshore. The small area of elevated NO₂ near Santa Barbara is related to the smoke plume from the Alisal fire, which burned through chaparral along the California coast in mid-October. Meanwhile, the blue area immediately over Los Angeles points toward reductions in urban emissions over the city core.

- “Part of what we may be seeing over Los Angeles is that the controls on mobile (trucks, cars, trains) and stationary (factories) sources of NO₂ that have come into effect in recent years have been effective, especially some of the controls at the port itself,” said Ted Russell, a Georgia Tech atmospheric scientist and member of a NASA Applied Sciences team focused on air quality. Since 2006, the LA and Long Beach ports have enacted a clean air plan that has led to significant reductions in NO₂ emissions.

- Other researchers note the COVID-related changes in transportation habits may be a factor. “The blue spot over downtown Los Angeles may be the result of fewer people commuting into offices downtown and working remotely instead,” said Daniel Goldberg, an atmospheric scientist at George Washington University. “When you are looking at satellite data showing changing concentrations of pollution, you always have to keep in mind that there are multiple factors at play that can be hard to disentangle.”

- Goldberg, Russell, and other atmospheric scientists all caution that other factors—especially wind and weather conditions—can make it quite challenging to interpret changes in nitrogen dioxide. “Double the wind velocity, and you can approximately halve the concentrations. Change the wind direction, and one area appears to have more, another less,” said Russell. One recent analysis by Goldberg found that strong winds or the direction of the winds could change NO₂ concentrations over Los Angeles by as much as 80 percent.

- In this case, it is possible that days with strong Santa Ana winds in 2018-19 could have exaggerated the apparent increase in NO₂ over Riverside and Irvine. “Without taking a careful look at the meteorology, what I can say is that this preliminary data certainly supports the idea that we’re seeing increased emissions offshore due to the shipping backlogs,” said Russell. “In another month or two, it might be possible to tell a much clearer story.”

• October 5, 2021: If it seems like enormous wildfires have been constantly raging in California in recent summers, it's because they have. Eight of the state’s ten largest fires on record—and twelve of the top twenty—have happened within the past five years, according to the California Department of Forestry and Fire Protection (Cal Fire). Together, those twelve fires have burned about 4 percent of California’s total area—a Connecticut-sized amount of land. ¹⁷⁾

​

​​

​

​​

- The total area burned by fires each year and the average size of fires is up as well, according to Keith Weber, a remote sensing ecologist at Idaho State University and the principal investigator of the Historic Fires Database, a project of NASA’s Earth Science Applied Sciences program. The database shows that about 3 percent of the state’s land surfaces burned between 1970-1980; from 2010-2020 it was 11 percent. The shift toward larger fires is clear in the decadal maps (above) of fire perimeter data from the National Interagency Fire Center.

- “The numbers are really worrisome, but they are not at all surprising to fire scientists,” said Jon Keeley, a U.S. Geological Survey scientist based in Sequoia National Park. He is among several experts who say a confluence of factors has driven the surge of large, destructive fires in California: unusual drought and heat exacerbated by climate change, overgrown forests caused by decades of fire suppression, and rapid population growth along the edges of forests.

​

​​

- “The current drought is unprecedented,” said Keeley. “Each of the past three decades has had substantially worse drought than any decade over the last 150 years.” In the short-term, drought exacerbates fires by sapping trees and plants of moisture and making them easier to burn. Over the long-term, it adds vast amounts of dead wood to the landscape and makes intense fires more likely.

- The 2020-2021 drought has been especially extreme. “The last two years in California have brought compound drought conditions—effectively, very dry winters followed by relentless summer heat and atmospheric aridity,” explained John Abatzoglou, a climate scientist at the University of California, Merced. “This has left soil and vegetation parched across much of California, so the landscape is capable of carrying fire that resists suppression.”

- Data from the Western Regional Climate Center indicates that the northern two-thirds of the state received only half of normal rainfall over the past few years. The U.S. Drought Monitor has categorized about 85 to 90 percent of California as experiencing “exceptional” or “extreme” drought for all of summer 2021. And the period between September 2019 and August 2021 ranked as the second-driest on record for the state, according to data from the National Centers for Environmental Information.

​

​​

- Daniel Swain, a climatologist at the University of California, Los Angeles, added that one of the most direct ways that climate change is influencing California fires is by dialing up the temperature. “Heat essentially turns the atmosphere into a giant sponge that draws moisture from plants and makes it possible for fires to burn hotter and longer,” he said. Meteorological data shows that the two-year period from September 2019 through August 2021 ranks as the third-warmest on record in California, with temperatures that were roughly 2.9° (1.6°C) degrees warmer than average. Air can absorb about 7 percent more water for every degree Celsius it warms.

- Abatzoglou noted that some of the harrowing scenes across Northern California in 2020 were due to an extreme and unusual dry lightning siege in mid-August that ignited thousands of fires in one night. “But in 2021 I am less convinced of bad luck,” he said. “Climate change is aiding in the warming and the more rapid drying of fuels that predispose the land to large fires.”

• September 24, 2021: As North America approaches the end of the 2021 water year, the two largest reservoirs in the United States stand at their lowest levels since they were first filled. After two years of intense drought and two decades of long-term drought in the American Southwest, government water managers have been forced to reconsider how supplies will be portioned out in the 2022 water year. ¹⁸⁾

- Straddling the border of southeastern Utah and northeastern Arizona, Lake Powell is the second largest reservoir by capacity in the United States. In July 2021, water levels on the lake fell to the lowest point since 1969 and have continued dropping. As of September 20, 2021, the water elevation at Glen Canyon Dam was 3,546.93 feet, more than 153 feet below “full pool” (elevation 3,700 feet). The lake held just 30 percent of its capacity. To compensate, federal managers started releasing water from upstream reservoirs to help keep Lake Powell from dropping below a threshold that threatens hydropower equipment at the dam.

​

​​

​

​​

​

​​

- Downstream in the Colorado River water management system, Lake Mead is filled to just 35 percent of capacity. More than 94 percent of the land area across nine western states is now affected by some level of drought, according to the September 23 report from the U.S. Drought Monitor.

- In an announcement on September 22, the U.S. Bureau of Reclamation (USBR) explained that updated hydrological models for the next five years “show continued elevated risk of Lake Powell and Lake Mead reaching critically-low elevations as a result of the historic drought and low-runoff conditions in the Colorado River Basin. At Lake Powell, the projections indicate the potential of falling below minimum power pool as early as July 2022 should extremely dry hydrology continue into next year.” Minimum power pool refers to an elevation—3,490 feet—that water levels must remain above to keep the dam’s hydropower turbines working properly.

- With the entire Lower Colorado River water storage system at 39 percent of capacity, the Bureau of Reclamation recently announced that water allocations in the U.S. Southwest would be cut over the next year. ”Given ongoing historic drought and low runoff conditions in the Colorado River Basin, downstream releases from Glen Canyon Dam and Hoover Dam will be reduced in 2022 due to declining reservoir levels,” the USBR statement said. “In the Lower Basin the reductions represent the first “shortage” declaration—demonstrating the severity of the drought and low reservoir conditions.”

​

​​

- The Colorado River basin is managed to provide water to millions of people—most notably the cities of San Diego, Las Vegas, Phoenix, and Los Angeles—and 4 to 5 million acres of farmland in the U.S. and Mexico. Water is allotted through laws like the 1922 Colorado River Compact and by a recent drought contingency plan announced in 2019.

- In a report and op-ed released on September 22, members of a NOAA Drought Task Force offered some context for the low water levels across the region. “Successive dry winter seasons in 2019-2020 and 2020-2021, together with a failed 2020 summer southwestern monsoon, led precipitation totals since January 2020 to be the lowest on record since at least 1895 over the entirety of the Southwest. At the same time, temperatures across the six states considered in the report (Arizona, California, Colorado, Nevada, New Mexico and Utah) were at their third highest on record. Together, the exceptionally low precipitation and warm temperatures reduced snowpack and increased evaporation of soil moisture, leading to a persistent and widespread drought over most of the American West.“

• September 20, 2021: Numerous craters on Earth are exceptionally compelling when viewed from space, displaying clearly visible rims and well-defined bowls. Not Sudbury Basin. It can take a moment looking at images to discern the shape of this impact structure amid the modern landscape. But few craters are as large or as old. ¹⁹⁾

- The object responsible for creating Sudbury Basin crashed into Earth about 1.8 billion years ago. That makes this crater in Canada fifty times older than Popigai—one of the world’s most well-preserved craters—which was created a mere 36 million years ago. Much of Sudbury’s original crater, thought to have measured at least 200 km (120 miles) across, has been deformed and eroded. Despite this, the crater has had a lasting impact on the region.

​

​​

- This region of Canada owes its unique geology to that powerful collision—initially thought to be an asteroid and later interpreted as a comet. The collision punctured Earth’s crust, allowing material from the mantle to well up from below and fill the basin with melted rock. Then after a shockwave shattered the surrounding rocks, minerals from the melted rock below infiltrated the cracks.

​

​​

- People have been making use of the minerals in Sudbury Basin for thousands of years. Large-scale mining operations started with the Murray Mine (now defunct) in the late 1800s. The mining took a toll on the landscape, polluting the region with sulfur dioxide and metals released during smelting processes. In recent decades, efforts have been made to capture emissions and restore the health of the basin’s land and water.

• September 17, 2021: In the midst of another brutal fire season that has threatened many lives, homes, and businesses, several of California’s natural treasures have also been threatened. Still burning after nearly nine weeks, the Caldor fire has encroached on Lake Tahoe. Now some of the world’s oldest and largest trees are being threatened by fires at the southern end of the Sierra Nevada range. ²⁰⁾

​

​​

- According to InciWeb and other sources, the KNP complex was ignited by a significant lightning storm on September 9–10. The Paradise fire and the Colony fire started separately near Sequoia National Park and have been marching across the drought-ravaged landscape toward a merger. By the morning of September 16, the KNP complex had burned 8,940 acres (36 km²). (A complex includes two or more separate fires that burn in very close proximity, have the potential to merge, and are managed by a unified firefighting group.)

- The KNP complex has led to the closure of Sequoia National Park and the evacuation of parts of the nearby community of Three Rivers. Fire officials told The Los Angeles Times on September 15 that the blazes were about a mile from the “Giant Forest,” the largest concentration of giant sequoias in the park and home to the 275-foot (83 m) General Sherman tree. Nearby Kings Canyon National Park remains open, but air quality is poor.

- The KNP fires are raging in very steep, dangerous terrain, so most of the firefighting has been done by aircraft so far. The National Park Service wrote in an update: “In the case of the Paradise Fire, extremely steep topography and a total lack of access has prevented any ground crew operations, and in the case of the Colony Fire, only a limited amount of ground crew access has been possible. Both fires are utilizing extensive aerial resources performing water and retardant drops.”

- Due south of the KNP complex, the Windy fire is burning in Sierra National Forest. It started in the Tule River Reservation during the September 9–10 lightning storm. About 2,800 acres have burned so far in an area not far from Giant Sequoia National Monument.

- According to CalFire, 1.97 million acres (nearly 3,100 square miles) have burned in California so far this year, and the fire season still has several months to go. The total is about half of the 2020 fire season—the worst on record—and roughly equal to the total burned in all of 2018. Near the end of the last severe drought in the state (2012-16), fire totals were 30 to 40 percent of the 2021 count.

​

​​

• September 12, 2021: Hurricane Ida left an extensive trail of damaged homes, infrastructure, and lives from Louisiana to New England. It also has left a stain on the sea. Two weeks after the storm, several federal and state agencies and some private companies are working to find and contain oil leaks in the Gulf of Mexico. ²¹⁾

- The U.S. Coast Guard has assessed more than 1,500 reports of pollution in the Gulf and in Louisiana, and it “is prioritizing nearly 350 reported incidents for further investigation by state, local, and federal authorities in the aftermath of Hurricane Ida.” The Coast Guard is working with the Environmental Protection Agency, the state of Louisiana, the National Ocean Service, and other agencies to chronicle and monitor the state of coastal waters and infrastructure.

​

​​

- Hurricane Ida caused the disruption of 90 to 95 percent of the region’s crude oil and gas production, while also damaging current and abandoned pipelines and structures. According to many news reports, the surface oil slicks near Port Fourchon (shown above) are likely related to as many as three damaged or ruptured submarine pipelines. It is unclear how much oil has spilled into the Gulf of Mexico.

- NOAA (National Oceanic and Atmospheric Administration) has conducted aerial surveys of some offshore waters and has released the photos online. The NASA-sponsored Delta-X research team has also been working in the area and was called upon to make some observations of the slicks and other coastal changes with synthetic aperture radar.

- Beyond active oil and gas extraction platforms, the seafloor of the Gulf of Mexico is covered in a maze of pipelines, capped wellheads, and other infrastructure that can be vulnerable to storm events. In a report issued earlier this year, the U.S. Government Accountability Office stated: “Since the 1960s, the Bureau of Safety and Environmental Enforcement has allowed the offshore oil and gas industry to leave 97 percent of pipelines (18,000 miles) on the seafloor when no longer in use. Pipelines can contain oil or gas if not properly cleaned in decommissioning.”

• August 30, 2021: Lake Mead is the largest reservoir in the United States and part of a system that supplies water to at least 40 million people across seven states and northern Mexico. It stands today at its lowest level since Franklin Delano Roosevelt was president. This means less water will be portioned out to some states in the 2022 water year. ²²⁾

​

​​

- The lake elevation data below come from the U.S. Bureau of Reclamation, which manages Lake Mead, Lake Powell, and other portions of the Colorado River watershed. At the end of July 2021, the water elevation at the Hoover Dam was 1067.65 feet (325 meters) above sea level, the lowest since April 1937, when the lake was still being filled. The elevation at the end of July 2000—around the time of the Landsat 7 images above and below—was 1199.97 feet (341 meters).

​

​​

- At maximum capacity, Lake Mead reaches an elevation 1,220 feet (372 meters) near the dam and would hold 9.3 trillion gallons (36 trillion liters, corresponding to 36,000 km³) of water. The lake last approached full capacity in the summers of 1983 and 1999. It has been dropping ever since.

- In most years, about 10% of the water in the lake comes from local precipitation and groundwater, with the rest coming from snowmelt in the Rocky Mountains that melts and flows down to rivers, traveling through Lake Powell, Glen Canyon, and the Grand Canyon on the way. The Colorado River basin is managed to provide water to millions of people—most notably the cities of San Diego, Las Vegas, Phoenix, and Los Angeles—and 4-5 million acres of farmland in the Southwest. The river is allotted to states and to Mexico through laws like the 1922 Colorado River Compact and by a recent drought contingency plan announced in 2019.

- With the Lake Mead reservoir at 35 percent of capacity, Lake Powell at 31 percent, and the entire Lower Colorado system at 40 percent, the Bureau of Reclamation announced on August 16 that water allocations would be cut over the next year. “The Upper [Colorado] Basin experienced an exceptionally dry spring in 2021, with April to July runoff into Lake Powell totaling just 26 percent of average despite near-average snowfall last winter,” the USBR statement said. ”Given ongoing historic drought and low runoff conditions in the Colorado River Basin, downstream releases from Glen Canyon Dam and Hoover Dam will be reduced in 2022 due to declining reservoir levels. In the Lower Basin the reductions represent the first “shortage” declaration—demonstrating the severity of the drought and low reservoir conditions.”

​

​​

- For the 2022 water year, which begins October 1, Mexico will receive 80,000 fewer acre-feet, approximately 5% of the country’s annual allotment and Nevada’s take will be cut by: 21,000 acre-feet (about 7% of the state’s annual apportionment). The biggest cuts will come to Arizona, which will receive 512,000 fewer acre-feet, approximately 18 % of the state’s annual apportionment and 8 % of the state’s total water use (for agriculture and human consumption). An acre-foot is enough water to supply one to two households a year.

• August 26, 2021: Since 2017, August 26 has been known as Katherine Johnson Day in West Virginia. The celebration commemorates the birthday of the ground-breaking NASA mathematician who was born on August 26, 1918, in White Sulphur Springs. ²³⁾

- Katherine Johnson contributed her mathematical expertise to the first human space travel missions in the United States. In 1953, in a time of racial segregation, she started a job as a human “computer” with the National Advisory Committee for Aeronautics (NACA), the predecessor to NASA. She worked in the West Area Computing section at Langley Research Center on a team of Black women headed by fellow West Virginian Dorothy Vaughan.

- In 1961, Johnson did trajectory analysis for Alan Shepard’s Freedom 7 mission, America’s first human spaceflight. Her work was also instrumental in John Glenn’s successful orbit around Earth in 1962.

- Glenn became a household name in the United States, but it wasn’t until recently that Katherine Johnson’s name became well-known. Her story came to light in 2016 through the book and film Hidden Figures by Margot Lee Shetterly. In a pivotal scene in the movie, John Glenn hesitated over trusting his fate in space to a network of new IBM computers. He asked Johnson to check the equations for his orbit against the computer output. “If she says they’re good, I am ready to go,” said Glenn.

​

​​

- Because of the segregated school system at the time, Black Americans could not attend high school in White Sulphur Springs. Her father moved the family to Institute, West Virginia, so that Katherine and her siblings could attend a high school that was on the West Virginia State University campus. Johnson graduated high school at 14, and then graduated summa cum laude from West Virginia State when she was 18, earning a double major in mathematics and French.

​

​​

- Johnson’s fingerprints are on some of NASA’s greatest achievements. She precisely calculated trajectories for the 1969 Apollo 11 flight to the Moon, and she worked on the Space Shuttle and the Earth Resources Technology Satellite (later renamed Landsat 1). Across three decades at Langley, she authored or co-authored more than two dozen research reports before retiring in 1986.

- In 2015, President Barack Obama awarded Johnson the Presidential Medal of Freedom, citing her as a pioneering example of African-American women in science, technology, engineering, and mathematics. “Katherine G. Johnson refused to be limited by society’s expectations of her gender and race, while expanding the boundaries of humanity’s reach,” said Charles Bolden, NASA's first Black administrator and a former astronaut.

- In 2019, NASA renamed its Independent Verification and Validation Facility in Fairmont, West Virginia, for Katherine Johnson. When she died on February 24, 2020, then-NASA Administrator James Bridenstine said: “She was an American hero and her pioneering legacy will never be forgotten.”

• August 17, 2021: Eleven years after an earthquake devastated the Haitian capital of Port-Au-Prince, another major earthquake has shaken the Caribbean nation. The epicenter of the magnitude 7.2 earthquake was centered about 100 km (60 miles) west of the 2010 quake, in a mountainous area between Petit-Trou-de-Nippes and Aquin. Like the previous event, this earthquake occurred along the Enriquillo-Plantain Garden fault, an area where two tectonic plates grind against each other. ²⁴⁾

​

​​

- The earthquake exposed more than one million people to very strong to severe shaking, according to the U.S. Geological Survey. In preliminary estimates, news media and Haiti’s civil protection agency are reporting large numbers of deaths and extensive damage to buildings and infrastructure.

- Many of the landslides in this image appear to be in sparsely populated areas. It is possible that landslides also occurred in areas south and east of the park that experienced intense shaking, but cloud cover on August 14 prevented Landsat from acquiring a clear view. Additional imagery from Landsat and other satellites should eventually provide more clarity about the extent of the landslides.

- The situation could be exacerbated in the coming days by heavy rains from tropical depression Grace. Some forecasts call for the storm to drop between 13 to 25 cm (5 to 10 inches) of rain on the areas hit hardest by the earthquake.

​

​​

- “Some hillslopes that have been destabilized by the earthquake but did not become landslides may be pushed past the limit of stability by the rain, leading to further landslides,” said Robert Emberson, a landslide expert with NASA’s Earth Applied Sciences Disasters Program. “Debris and rock already mobilized by the earthquake may be transported by flash flooding as devastating debris flows. The material is mostly at the base of hills currently, but rivers quickly filled by rain could push that downstream and cause severe impacts to communities living farther from the location of the landslides.”

- NASA’s disasters program is monitoring the situation and coordinating with the United States Agency for International Development and other partners to share relevant data about the event with emergency responders. Data and updates from the team will be shared here.

• August 12, 2021: In the first two weeks of August 2021, Greece has endured a series of wildland fires that have charred a large swath of the island of Evia and several areas of the Peloponnese region. The fires followed closely after one of the worst heatwaves in the country since the 1980s, which dried up scarce moisture and left forests primed to burn. Greek Prime Minister Kyriakos Mitsotakis told several news agencies that the fire outbreak has been a “disaster of unprecedented proportions.” ²⁵⁾

​

​​

- According to data from the European Forest Fire Information System (EFFIS), more than 110,000 hectares (424 square miles) have burned in Greece this year, more than five times the yearly average from 2008 to 2020 (21,000 hectares). EFFIS counted 58 fires (30 hectares or larger) in the country in 2021, already above the yearly average total of 46.

​

​​

- Some of the worst fires in the country have burned on Evia, the second largest island in Greece and a major hub for tourism. Much of the island has been in a state of high fire alert for a week. The Associated Press reported that an estimated 50,000 hectares (123,000 acres) have burned on Evia, as well as hundreds of homes.

- Significant fires also broke out near Athens, Olympia, and Arcadia, and 63 organized evacuations have been reported across Greece in the past nine days. Firefighters and equipment have been sent from at least 15 countries to help Greek authorities.

- As of August 11, EFFIS reported that more than 338,000 hectares (1,300 square miles) have already burned across Europe in 2021, more than the 2008-2020 average for an entire year (295,000). More than 109,000 hectares have burned so far in Italy, 2.5 times the annual average. Large fires have also been burning in Algeria and Turkey.

​

​​

- The heatwaves and fires fit with patterns described in the latest assessment report from the Intergovernmental Panel on Climate Change (IPCC), to which NASA-funded scientists contribute. In its summary of climate conditions in Europe, the IPCC noted: “The frequency and intensity of hot extremes ... have increased in recent decades and are projected to keep increasing regardless of the greenhouse gas emissions scenario. Despite strong internal variability, observed trends in European mean and extreme temperatures cannot be explained without accounting for anthropogenic factors.”

• August 11, 2021: Every year, scientists at the University of Maryland publish new data about the state of Earth’s forests based on observations from Landsat satellites. As has often been the case in recent years, the update for 2020 painted a bleak picture. In that one year, Earth lost nearly 26 million hectares of tree cover—an area larger than the United Kingdom. ²⁶⁾

​

​​

- The raw numbers can tell us how much and where forests were lost, but they do not explain what was driving those losses. How much deforestation was due to wildfires? Food production? Forestry management? An ongoing effort by researchers from The Sustainability Consortium and the World Resources Institute (WRI) attempts to answer such questions with maps and datasets that categorize and quantify the major drivers of annual forest losses. In doing so, the researchers have put a spotlight on the impact that food production has on forests, particularly in the tropics.

- In 2020, for instance, Earth lost about 4.2 million hectares (16,000 square miles) of humid tropical primary forest—an area about the size of the Netherlands. Nearly half of that, their analysis shows, was due to food production, and half of that was due to commodity crops. In recent years, commodity crop production has pushed rates of forest loss to record levels.

​

​​

- “In many cases, commodity-driven deforestation is essentially a permanent change compared to shifting agriculture,” explained Christy Slay, a conservation ecologist and the senior director of science and research applications at The Sustainability Consortium. “These areas will likely never be forests again.”

- In contrast, forests cleared for forestry management or by wildfires generally grow back over time. In the U.S. Southeast, for instance, managers maintain certain ecosystems and animal habitats by periodically burning and planting forests to mimic natural cycles of burning and regrowth. Likewise, forests in the Pacific Northwest and Europe are often managed for timber in ways that cycle between periods of forest clearing and periods of regrowth.

- Note that food production was once a major driver of deforestation in North America and Europe, but much of the clearing happened a hundred or more years ago. Since many forests in these areas were already gone by 2000, their absence does not register as forest loss. Nor does the map capture the impact of large-scale conversion of natural grasslands to agriculture, a common practice in both North and South America.

- With tropical forest cover dwindling and the effect of climate change becoming more acute, some companies and consumers are trying to ensure that food production does not lead to new deforestation. In recent years, hundreds of companies have committed to eliminating or reducing products in their supply chains that cause deforestation. But ensuring that is often challenging.

- “Global supply chains can be complicated and opaque,” said Slay. “You often have companies buying commodities off the spot market, such that the source regions change frequently or even daily. Retailers and food manufacturers often don't know the source of their ingredients down to the individual farm and field scale.”

- By regularly collecting data on the health of forests, satellites are making it easier for scientists to untangle which commodities and regions are the biggest contributors to deforestation. Doug Morton, a forest ecologist at NASA’s Goddard Space Flight Center, has witnessed a shift in the dominant drivers of deforestation.

- “Forty years ago, we often saw small-scale deforestation creating roads that look like fishbone patterns,” said Morton, who monitors agricultural frontiers in the Amazon. At the time, many people were moving into the Amazon to escape drought and hunger in eastern Brazil. “By the middle of the Landsat record, we see large-scale commodity production taking hold. Today’s deforestation isn’t about individual families. It’s often tractors and bulldozers clearing large tracts of forest for industrial scale cattle ranching and crops.”

- For companies trying to keep their supply chains free of deforestation, knowing which commodity crops are being grown where is critical. “If we know where deforestation is common and what crops are involved, we can go to companies and say: ‘Be careful if you’re working with suppliers that are sourcing this particular product from this particular part of the world,’ ” said Slay. “Satellite data of forest change and loss is the first step in the process.”

- One recent WRI analysis combined Landsat imagery with economic and land-use data to parse the impact of seven different commodities on forests around the world. “One of the big things you notice in the data is the outsized role of cattle pastures in driving deforestation,” said Mikaela Weisse, one of the report’s authors. “Cattle pastures caused about five times more deforestation than any of the other commodities we analyzed.”

​

​​

- In Southeast Asia, where deforestation rates have dropped recently, most forest losses are associated with palm oil, which is used in many types of processed foods and various health and beauty products like deodorant, shampoo, toothpaste, soap, and lipstick. Deforestation for cocoa production had a sizable impact in certain countries—notably Ghana and Côte d'Ivoire—but only represented 3 percent of total forests losses. Other commodities with similarly modest effects on global forests included rubber, coffee, and wood fiber.

- While new tools are making it easier to understand where food production is intersecting with new deforestation, huge challenges remain. “Deforestation rates are going up instead of down,” said Elizabeth Goldman of WRI. “There’s a lot of work left to do.”

• August 4, 2021: In the midst of a severe heatwave and following months of dry weather, Turkey is facing some of its worst wildfires in years. Over the past seven days, more than 130 wildfires have been reported across 30 Turkish provinces. Most of the fires have ignited along the Mediterranean and Aegean Sea coasts, several in resort areas around Antalya, Mugla, and Marmaris. ²⁷⁾

​

​​

​

​​

- The European Forest Fire Information Service reported more than 136,000 hectares (525 square miles) have burned in Turkey already this year, about three times the average for an entire year. The European Space Agency’s Sentinel-3 satellite also acquired a view of the fires on July 30.

​

​​

- Fires were still being fed by strong winds, air temperatures above 40º Celsius (104° Fahrenheit), and low humidity. Croatia, Iran, Spain, Russia, Ukraine, and Azerbaijan provided equipment and personnel to help Turkish firefighters bring the blazes under control.

- Much of southern Europe has been baking for weeks under extreme heat not seen since the 1980s. National temperature records were set in both Greece and Turkey in the past month. Air temperatures reached 45°C (113°F) in Greece and surrounding areas yesterday, and the heat is forecasted to continue for several days. Fires are also burning this week in Greece and Lebanon.

• July 21, 2021: Covered with lakes, forests, and mountains, Dalarna County has been called “Sweden in miniature.” But the same region that today draws people to its idyllic lakeside villages and midsummer celebrations was also the site of an ancient, catastrophic impact. ²⁸⁾

​

​​

- Around 380 million years ago, in the Late Devonian period, an asteroid slammed into the land that is now south-central Sweden. The impact left quite a mark. Even after hundreds of millions of years of erosion, the scar is still recognizable. It is especially apparent when viewed from above.

- Surveys of the structure have shown that the ground is slightly raised up across parts of the crater’s center. It is surrounded by a ring-like graben, or depression, which today is partially filled with water. Lake Siljan, on the crater’s southwest side, is the largest lake; it connects to Lake Orsa via a small river.

- People have lived for millennia near the crater without knowing its cosmic origin. In the late 1960s, scientists used drill cores to uncover the complex and ancient geology deep below the ground.

- Research at Siljan is ongoing today. In a 2019 study, scientists described how they used drill cores to find that the deep, fractured rocks in the crater were suitable for ancient life. A subsequent paper in 2021 described the fossilized remains of fungi discovered at a depth of more than 500 meters.

• July 19, 2021: For several months, communities along the west coast of Florida have observed substantial blooms of the harmful algae Karenia brevis. The algae occur naturally in the waters around Florida, but the bloom in 2021 has been particularly bad near Tampa Bay, causing large-scale fish kills in what some people refer to as a ‘red tide’ event. The bloom is also unusual for how early it is occurring. ²⁹⁾

​

​​

- Karenia brevis is a microscopic algae that, like other phytoplankton, can multiply into massive blooms when there are enough nutrients in the water—often in the autumn along the Gulf Coast. The algae produce neurotoxins that can kill fish and cause skin irritation and respiratory problems for humans, particularly those prone to asthma and other lung diseases. In extreme concentrations, K. brevis can turn water brown, red, black, or green; however, it is not always visible from space.

​

​​

- “This Karenia brevis ‘red tide’ bloom is doubly unusual,” said Richard Stumpf, an oceanographer for the National Oceanic and Atmospheric Administration (NOAA). “It is summer, which is rare, and it is intense well into Tampa Bay, which is rare even during a ‘normal’ fall bloom.”

- “If a bloom is out on the continental shelf, it is more easily diluted,” said Chuanmin Hu, an optical oceanographer at the University of South Florida (USF). “The bloom this year is so troublesome because it is both inside Tampa Bay and around the Tampa Bay mouth.”

​

​​

- “Although Karenia brevis blooms are common to the West Florida Shelf and have been observed in almost every coastal region of the Gulf of Mexico, I have never seen anything like that inside Tampa Bay,” said Inia Soto Ramos, an ocean color specialist at NASA’s Goddard Space Flight Center (GSFC) and former researcher at USF. “Massive blooms were observed back in the late 1990s, and even the Spanish conquistadors described them in their books. But the bloom this year inside the bay is worrisome. It could be a one-year thing, and hopefully it is. But if water quality in the bay continues to decline, residents should prepare for more blooms, and not only K. brevis.”

- Since early June 2021, Karenia brevis has been abundant along the Gulf Coast from just north of Clearwater to Sarasota. In a July 14 report, the Florida Fish and Wildlife Conservation Commission noted: “A bloom of the red tide organism, Karenia brevis, persists on the Florida Gulf Coast. Over the past week, K. brevis was detected in 107 samples.”

- According to the Sarasota Herald-Tribune, coastal work crews have collected more than 600 tons of dead fish and marine life killed by the bloom. On July 15, the city council of St Petersburg asked the governor to declare a state of emergency over the bloom. Officials are still trying to pinpoint the trigger for the event, but many scientists note that the area has been unusually rich with algae-sustaining nutrients in 2021.

- “Karenia brevis blooms, although studied for decades, do not follow a strict recipe. Some years, circulation and advection are the main drivers,” said Soto Ramos. “However, we know if there is an excess of nutrients, the algae will utilize them. I think the bloom right now is due to a combination of available nutrients, warm temperatures, and circulation patterns keeping the algae contained within the bay. Once the algae are there, they stay for a while.”

- NASA is currently developing the Plankton, Aerosol, Cloud, ocean-Ecosystem (PACE) satellite mission for launch around 2024. The satellite is being designed with sensors tuned to the signatures of blooms. “Whereas heritage ocean color instruments observe roughly six visible wavelengths, PACE will collect a continuum of colors that span the visible rainbow,” said Jeremy Werdell, project scientist for PACE at NASA GSFC. “Its ocean color instrument will be the first of its kind to collect hyperspectral radiometry on global scales, which will allow unique and highly advanced identification of aquatic phytoplankton communities, including potentially harmful algae such as these on the West Florida Shelf.”

• July 17, 2021: In recent decades, aquaculture has boomed in Andhra Pradesh. The state has become one of India’s largest producers of farmed fish and shrimp. Among the reasons for the boom:a major expansion a of inland aquaculture farms along rivers and canals where people once raised crops. ³⁰⁾

​

​​

- According to satellite imagery, aquaculture was scarce in this area in the mid-1980s. Now carp, catfish, and other types of finned fish are commonly raised in the area. There are numerous shrimp ponds, too, which tend to be the narrow according to one satellite survey of the area.

- The Indian government established the first aquaculture ponds in this area in the 1970s around Lake Kolleru. Since then, the initial success of those projects has made aquaculture an appealing and profitable choice for many farmers in the region who regularly dealt with crops being flooded, the intrusion of salt into water used for irrigation, and Bay of Bengal cyclones.

​

​​

- Despite the expansion, India’s aquaculture sector has faced challenges recently. One recent study calculated that its shrimp farming sector may have lost as much as $1.5 billion in 2020-2021 due to disruptions related to the pandemic. The state of Andhra Pradesh accounts for about 70 percent of India’s shrimp production.

• July 11, 2021: In research published in 2017, scientists reported that summer pulses of freshwater from melting glaciers along Greenland’s southwest coast often coincide with phytoplankton blooms. The flow of fresh meltwater out to sea carries nutrients that can sustain and promote abundant growth of the floating, plant-like organisms that form the center of the ocean food web. ³¹⁾

​

​​

- The waters of the Labrador Sea, Davis Strait, and Baffin Bay—between Greenland and Nunavut, Canada—form a transitional zone between the Arctic and Atlantic oceans. Fresh meltwater from the ice sheets and strong regional tides (which promote nutrient mixing) help make these waters biologically rich, particularly in summertime. The abundant phytoplankton draw in copepods and other grazers that ultimately feed shrimp, cod, and other species up to the size of whales.

- In the 2017 paper, Stanford University ocean scientist Kevin Arrigo and colleagues noted that summer blooms tend to start in early July and can extend as far as 300 kilometers (200 miles) offshore from Greenland. Fed by sunlight and water rich in iron, silicate, and phosphorous, the blooms account for about 40 percent of annual net primary production for the region.

- Blooms in high-latitude and Arctic waters are happening more often and lasting longer, according to another study published in 2020 by Arrigo’s research group. Incorporating satellite data from NASA’s SeaWiFS and MODIS instruments, they found that the rate of growth of phytoplankton biomass across the Arctic Ocean increased by 57 percent between 1998 and 2018. The study contradicted an older idea that increasing glacier melting might lead to fewer nutrients and blooms.

• July 8, 2021: Toward the end of the last Ice Age, as mile-thick glaciers weighed down the land surface and then melted, parts of New England and eastern Canada became inundated by water. Some lowlands flooded and formed inland basins like the Champlain Sea. ³²⁾

- Ten thousand years later, with seas now rising because of global warming, scientists are combing through an array of data and building increasingly detailed models to understand the processes that drive regional and local changes in sea level. The goal is to project when, where, and how much seas are likely to rise in the coming decades and centuries. It's an incredibly complicated set of interdependent calculations.

​

​​

- “People tend to think that sea level is like a bathtub with the water level simply rising and falling depending on how much water is coming out of the faucet,” said paleoclimatologist Anders Carlson of the Oregon Glaciers Institute. “In reality, it’s more like a spinning bathtub that’s changing shape, moving up and down, and has water pouring into and out of different drains and over the sides. Where the water will ultimately slosh over the edge of the tub is influenced by many things, making it difficult to say where the overtopping will occur.”

- Despite the complexities, the scientific understanding of the factors that control sea level has improved dramatically in recent decades, as have measurements of past sea level change and projections of future change.

- “We can tell you how much the ocean has warmed in recent decades, and how much more space the water takes up. We have satellites and other tools that have measured that,” said Ben Hamlington, the current lead of NASA’s sea level change team. “The same thing is true for several of other factors that influence sea level, such as the mass of the ocean, the salinity, and how much water is stored on land.”

- That growing knowledge base is why scientific organizations like the Intergovernmental Panel on Climate Change (IPCC) are publishing sea level rise projections with increasing levels of confidence. In its 2019 report, the IPCC projected (chart Figure 64) 0.6 to 1.1 meters (1 to 3 feet) of global sea level rise by 2100 (or about 15 mm per year) if greenhouse gas emissions remain at high rates (RCP8.5). By 2300, seas could stand as much as 5 meters higher under the worst-case scenario. If countries do cut their emissions significantly (RCP2.6), the IPCC expects 0.3 to 0.6 meters of sea level rise by 2100.

- A host of competing factors will influence how global sea changes translate to regional and local scales. Among them: the rising or falling of the land surface due to plate tectonics and human activity; gravity anomalies that can create regional bulges and dips in sea surface height; variations in the temperature and salinity of seawater; changes in the amount of water stored on land in reservoirs; isostatic adjustment due to the addition, loss, and movement of land ice; and changes in erosion and how much sediment rivers carry to coastal areas.

​

​​

- But it is hard to predict human settlement patterns—and the subsidence it causes—decades or centuries from now. Many IPCC projections do not even attempt to incorporate estimates of this subsidence partly because of the uncertainties in future land use and human behavior and because there is a lack of readily available, large-scale data on vertical land motion to feed into models of sea level rise.

​

​​

- Likewise, teams of scientists have been surveying the fast-sinking Mississippi River Delta to get a better understanding of how changes in sediment and vegetation affect the delta. Scientists participating in NASA’s Delta-X campaign have collected several types of data to develop and calibrate a model of how the delta might respond to rising sea levels in the next century.

- “The combination of anthropogenic subsidence and increasing rates of sea level rise is a five-alarm fire for many delta cities,” said Shirzaei. “Places like New Orleans, Kolkata, Yangon, Bangkok, Ho Chi Min City, and Jakarta will undoubtedly face increasing pressures from flooding and saltwater intrusion.”

- Still, the long-term picture—hundreds of years into the future—is unlikely to be perfectly clear. “When you think about future impacts of sea level rise, you also have to consider what people might do in response," said Hamlington. Some countries—like The Netherlands and the United States—have already built elaborate sea walls and water-control systems that protect vulnerable deltas like the Rhine and the Sacramento-San Joaquin. They will likely continue reinforcing these systems as sea levels rise. In others deltas, like the Krishna (Figure 65) or Ganges in India, the Chao Phraya in Thailand, and the Mekong in Vietnam, coastal defenses are more limited so far.

- “The reason people within the scientific community are working so hard on regional sea level rise projections is that if we can get them right, it will give cities and nations a chance to prepare,” said Hamlington. “Even if some of the more distant projections are inexact, they still provide critical constraints that could end up being the difference between places that successfully adapt to rising seas and those that experience the most damaging consequences.”

• July 6, 2021: With heights ranging from 600 to 1800 meters (2,000 to 5,900 feet), the Barberton Makhonjwa Mountains in South Africa and Eswatini are not particularly tall. What distinguishes the belt of greenstone rock formations found here is their age. ³³⁾

​

​​

- Beneath the rolling, grassy uplands and forested valleys of the mountain range, lie some of the oldest, best-preserved, and diverse sequences of volcanic and sedimentary rock layers found anywhere on the planet. They hold evidence of some of Earth’s earliest forms of life, including microfossils, stromatolites, and other biologically derived material. Geological sampling indicates that some rock formations in these mountains are 3.2 to 3.6 billion years old.

- One type of rock in this area that especially intrigues geologists is komatiite. The rare igneous rock formed from magmas that were hotter, more liquid, and denser than any lavas found on Earth today. Geologists still debate what conditions allowed komatiite to form, but many think Earth’s mantle was likely hotter or wetter 3 billion years ago than today, and that likely played an important role.

• July 3, 2021: On March 19, 2021, the Fagradalsfjall volcano erupted after lying dormant for 800 years. Three months later, the volcano on Iceland’s Reykjanes peninsula is still spewing lava and expanding its flow field. ³⁴⁾

​

​​

- The Icelandic Met Office reported that by May 3, the lava flow was largely confined to one main crater, a fifth fissure that opened in April. In late May, lava flows broke through an artificial barrier built to contain it; the lava continued flowing south towards Nátthagi Valley. The lava flow has since cut off access to the most popular hiking trail to the eruption site. As of June 15, the lava flows were estimated to cover a total area of 3 square kilometers (about 1 square mile), with an estimated volume of 63 million cubic meters.

- Icelandic officials are concerned that a prolonged eruption will cause lava to flow south and cross the Suðurstrandarvegur, a road used to transport goods and connects Reykjanes peninsula to South Iceland. After crossing the road, the lava flow could continue toward the ocean.

• June 30, 2021: Skies were clear and the waters of Mistastin Lake were placid when the Operational Land Imager (OLI) on Landsat 8 captured this natural-color image of Labrador, Canada, on a fall day in 2017. ³⁵⁾

​

​​

- The scene would have looked quite different about 36 million years ago when an asteroid smashed into Earth and left an impact crater where the lake (called Kamestastin by the Innu people) now sits. While erosion has changed and obscured some of the features, a 50-meter (164-foot) wall still rings much of the crater. Geologists estimate the original crater had a diameter of about 28 kilometers (17 miles)—about twice the size of the current lake.

- Parts of the central peak are also visible in the lake as Horseshoe Island. These mound-like features are often found in the center of large craters as a product of the melting and rebound of subsurface rocks. Meanwhile, the elongated, elliptical appearance of the crater is a result of periods when glaciers slid across this area during several ice ages.

- Based on the presence of an unusual diamond-like mineral called cubic zirconia, the asteroid impact must have heated rocks at the site to at least 2370°C (4,300°F). That would be the hottest-known temperature recorded by a surface rock on Earth, according to one team of researchers.

• June 21, 2021: The Yukon-Kuskokswim Delta is one of the world’s largest deltas, and it stands as remarkable example of how water and ice can shape the land. These images show the delta’s northern lobe, where the Yukon River spills into the Bering Sea along the west coast of Alaska. ³⁶⁾

​

​​

- While the image could be considered a work of art, there are some useful aspects to looking at the land this way. For example, you can easily distinguish areas of live vegetation (green) from land that is bare or contains dead vegetation (light brown) from the network of sediment-rich rivers and ponded flood water (dark brown). A sprinkling of thermokarst lakes are also part of the scene.

​

​​

- In general, the green areas across the delta are tall willow shrublands. They are especially apparent on either side of the river channels in the detailed image above. The light-brown areas are primarily moist sedge meadows; they appear brown because much of it is the dead remains of last year’s growth. Away from the delta (right side of the image) the vegetation is shrub-tussock tundra.

- “To me, one of the interesting things about the delta is that it is a highly transitional area, with some elements of Arctic tundra and some of boreal forest,” Frost said.

- The delta also transitions with the seasons. At the time of this image, the signature of spring flooding is written across the delta. Melting snow and ice cause the rivers to spill over their banks and by late May, many of the marshes are filled with floodwater, which appears as dark-brown ponds.

- According to Lawrence Vulis, a graduate student at the University of California, Irvine, the delta would have appeared much more inundated immediately following the melting of snow and ice a few weeks prior to this image. Stream gauges and satellite images suggest that the bulk of the flooding had already subsided. Still, the flooding was recent enough that the plenty of ponding remained on May 29. As summer advances, the floodwater will continue to recede and the wetlands will continue to green up with vegetation.

- Also notice the colorful water where the delta meets the Bering Sea. This is a product of glacial runoff far upstream, which carries a large amount of sediment toward the coast. This sediment is also instrumental to the formation of tall “levees” on the sides of the channels, deposited there when floodwaters spill over their banks. These “levees” support stands of tall willows—important habitat for moose.

- “Interestingly, tall shrubs have expanded a lot on the delta in recent decades, and the moose have followed,” Frost said. “Today, the delta has one of the highest moose densities in the state of Alaska.”

- The delta did not always look this way. Studies have shown that the modern Yukon Delta is just a few thousand years old. It’s young age “is incredible to think about,” Vulis said. “We are used to thinking about relatively ancient landscapes, but modern river deltas have only formed in the last 10,000 to 8,000 years since global sea level has stabilized.”

- The delta could quite possibly look different in the future. “The Yukon and other Arctic deltas are thought to be particularly vulnerable to climate change,” Vulis noted, “due to the roles of permafrost and ice in shaping these deltas.”

• June 16, 2021: Over the past three decades, small-scale gold mining has led to more than 100,000 hectares (250,000 acres) of forest loss in the Peruvian Amazon. While government agencies and conservation groups have successfully curbed such activity in recent years, new mining hotspots still pop up in unauthorized zones. ³⁷⁾

​

​​

- Peruvian researchers from Conservación Amazónica (ACCA), working with NASA and the Peruvian government, have developed a satellite-based tool to locate emerging mining hotspots in the Amazon. The Radar Mining Monitoring Tool (RAMI) identifies areas that appear to have new mining activity and examines their proximity to protected buffer zones, indigenous lands, mining concessions, and already degraded lands. The information is shared with Peruvian authorities to help pinpoint new activity and stop illegal mining.

- “Authorities may have limited resources to find all of the mining hotspots in a region,” said Sidney Novoa, project manager for SERVIR-Amazonia and a researcher at ACCA. “There are many systems that monitor forests in Peru, but no one else is focused just on gold mining. Our main goal is to empower authorities and give them enough resources to prioritize and focus their efforts.”

​

​​

- The research team is particularly interested in detecting small-scale, artisanal gold mining, typically operated by independent miners known as garimperos. In recent decades, the number of artisanal mines in the Madre de Dios department of Peru has increased, carving out a larger environmental footprint than industrial mines. Artisanal miners use mercury, which can pollute water sources and lead to neurological disorders or kidney issues in humans who are exposed to it. Illegal mining in protected zones also can compromise the homes of indigenous people, as well as endemic plants and animals.

​

​​

- “I used to put aside looking at mining activity during the rainy season because authorities thought it would not occur intensely during those months,” said Novoa. “We finally have information to demonstrate the importance of monitoring mining activities during the rainy season.” He explained that activity typically intensifies once the peak of the rainy season passes in February and March, as garimperos use the accumulated water in forests and waterways for their mining.

- RAMI mining alerts are updated every 15 days depending on the availability of satellite data. Novoa’s team creates private reports about new hotspots for the Monitoring of the Andean Amazon Project (MAAP), an initiative from Amazon Conservation Association and ACCA. Summaries are also shared directly with Peruvian authorities. The RAMI tool is hosted on the Internet and open to the public.

- RAMI is supported by SERVIR-Amazonia, a joint program of NASA and the U.S. Agency for International Development (USAID) that uses remote sensing to provide support for sustainable development. It is led locally by the Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT). The RAMI tool was co-developed with and incorporated data from ACCA, Peru’s Ministry of Environment, and Peru’s National Forest Conservation Program.

• June 15, 2021: People have been mining for gold in Ghana for centuries. Long before European colonists set foot in the area in the 1400s, Ghanaians looked for gold with pickaxes, shovels, and pans. They washed or “panned” for gold along river banks or dug holes on the surface to find deposits of gold dust and nuggets. Serious indigenous miners dug deep tunnels—records indicate some up to 80 feet deep. ³⁸⁾

​

​​

- A version of this small-scale mining persists—known today as artisanal mining—but new research shows it is having a growing and sometimes devastating effect on the environment. Researchers from NASA, U.S. universities, and government agencies in Ghana recently used satellite data to estimate the extent of vegetation lost to artisanal mining in the southwestern portion of the country, where the majority of gold mining takes place. They found artisanal mining accounted for 25 percent of vegetation loss in the region from 2005-2019.

- “The accumulation of the small-scale mines across the landscape is startling. The deforestation impact is huge compared to industrial mines,” said Abigail Barenblitt, the main author of the study and data analyst in the biosphere sciences lab at NASA’s Goddard Space Flight Center. Although it only accounts for about one-third of the country’s gold production today, artisanal mining caused seven times more deforestation than industrial efforts between 2007-2017.

- The differing impact of artisanal and industrial mines is related to the process of gold extraction, said study co-author Amanda Payton of East Carolina University. Large-scale industrial mines use heavy machinery to dig deep in a concentrated area. Industrial miners are also sometimes required to fill the holes in the landscape after extraction in order to help with remediation.

- Because they typically do not have heavy-duty equipment, artisanal miners tend to dig many shallow holes across large swaths of land. They extract and process gold at the site and then move onto the next area. They usually do not refill holes after extractions. And they often use mercury to remove gold from sediments, which can lead to serious health problems and long-term water and soil contamination. Unregulated artisanal mining is locally known as galamsey, derived from the Ghanaian words “gather” and “sell.”

- “Artisanal mining has a quicker turnaround time on the landscape, with operations excavating a shallower area and then moving on to another section of the river. Some of the artisanal mines stretch for great distances along rivers,” said Payton. “With industrial mining, more research into the gold deposits is done and more resources are committed to a single area of land to excavate deeper.”

- Barenblitt, Payton, and colleagues worked with the Ghana Space Science and Technology Institute and Ghana Statistical Service to determine the total footprint of vegetation loss to artisanal gold mining. They analyzed decades of Landsat data, creating a machine-learning algorithm to classify any vegetation loss in one of four categories: mining, urban development, water, and other (agriculture, bare soil, etc.). The team found more than 160,000 hectares (400,000 acres) of vegetation were lost from 2005-2019. About 28 percent was lost to both industrial and artisanal gold mining, while 29 percent was lost to urban development. About 17 percent was converted to water, mainly due to the formation of a lagoon complex. The remaining 25 percent was attributed to the “other” category of land losses.

- The team further classified mining as large-scale industrial or small-scale artisanal by looking at elevation data and the texture of the landscape. Industrial mines have larger elevation changes since they dig deeper into the surface. Highly textured landscapes tend to indicate artisanal mining due to the small holes compared to wider, smoother industrial areas. Artisanal mines accounted for 85.7 percent of vegetation loss, while industrial mines accounted for 14.3 percent from 2005-2019.

​

​​

​

​​

- “There has definitely been an expansion of small-scale mining by more people over time because of the price of gold,” said Lola Fatoyinbo, a forest ecologist at NASA’s Goddard Space Flight Center and a contributor to the study. “The high gold prices probably made artisanal mining worth the labor.” The team calculated a correlation between gold prices and annual mining conversion after a two-year lag. Over the study period, the value of gold jumped from about $700 per ounce to as high as $1,700 in 2012; it is now nearly $1,800 per ounce.

- The team’s next step is to automate their image analysis process so new mining can be detected quickly by African and international organizations addressing the issue. This research is part of larger efforts across NASA to detect unregulated gold mining in Ghana. The team has collaborated and compared methods with researchers of SERVIR-West Africa, a program between NASA and the U.S. Agency for International Development (USAID). SERVIR-West Africa uses similar mining analyses and shares the data to government officials to help curb artisanal activities and reform past mining sites.

• June 4, 2021: Off the coast of Sonoma and Mendocino counties, changing climate and a marine epidemic have combined to decimate one of California’s most productive ecosystems. In the span of a single year, the region’s renowned kelp forests almost completely collapsed, and they are still struggling. Floating forests that once harbored and fed many marine species have turned into barrens devoid of biodiversity. ³⁹⁾

​

​​

- Using 34 years of Landsat imagery, a team of researchers led by Meredith McPherson of the University of California, Santa Cruz, documented the fast and catastrophic collapse of the once hardy kelp forest, as well as its struggle to regenerate. The research team found that the Northern California kelp canopy declined more than 95 percent in 2014-15, and the effects persisted for five years.

​

​​

- Bull kelp is a canopy-forming macroalgae that flourishes in nutrient-rich, cool water and grows as much as 60 cm (nearly 2 feet) per day. The kelp is considered an “ecosystem engineer”—the foundational species of a nearshore ecosystem that feeds and shelters other marine life. It is the dominant kelp species north of Monterey Bay, California, with underwater forests thriving along 160 km (100 miles) of rocky reefs from Fort Bragg to Jenner.

- Unlike the giant kelp more common to the south, bull kelp is an annual species that grows vigorously from June through August. It then disperses its spores before fall and winter storms dislodge the mature plants from their rocky perches. While the exact location and extent of the bull kelp can change from year to year (based on spore dispersal and environmental factors), the underwater forest has historically regenerated regularly.

- Looking across several decades of Landsat observations, McPherson and colleagues found that the geographic distribution of bull kelp contracted, first receding in 2008 in the sandier regions north of Fort Bragg, and then in 2012 in sandier sections south of Jenner. (These areas are just north and south of the map area shown.) But along the rocky substrate in the middle, the bull kelp held strong.

​

​​

- The nutrient-poor waters associated with marine heatwaves hinder kelp growth, leading to smaller canopies. Historically kelp have been resilient, though, coming back in force once waters have cooled down. But this time, a cascading series of environmental and biological events—exacerbated by climate change—combined to decimate the forests.

- The delicate interplay of species that safeguards kelp forest biodiversity was shifted in 2013 when more than 20 sea star species from Alaska to Mexico started wasting away. In particular, sunflower sea stars, the primary predator of kelp-devouring purple sea urchins, were ravaged by a mysterious wasting syndrome. Renowned regenerators known to grow back entire limbs, the sea stars (starfish) looked as if they had melted to goo.

​

​​

- By 2015, the kelp forests were mostly gone, replaced by urchin barrens. Divers described the conversion of once-rich kelp forests into spiky purple carpets. With no kelp left to eat, the purple sea urchins now mostly subsist in a starvation state, rousing occasionally to eat any nascent kelp that tries to establish itself. These zombie urchins are effectively killing the chances of kelp recovery.

- The loss of bull kelp forests has meant the loss of the ecosystem services they rendered. California’s recreational abalone fishery—the world’s largest, with over 35,000 fishers—was closed in 2018 after more than 80 percent of these edible sea snails died for lack of kelp sustenance. Kelp harvesting and recreational diving have been clobbered, too. The ecosystem also lost capacity to sequester carbon—kelp are 20 times more efficient than their terrestrial counterparts—and to temper the destructive power of waves.

- Restoring the kelp forests is a priority for marine managers, but it is a massive challenge. The purple urchins are of little nutritional interest to most predators or fishermen in their diminished state, yet they have still been observed spawning. A group of citizen scientists known as Reef Check has taken to diving to remove the urchins manually in an effort to create small urchin-free oases where new kelp can grow. In 2020, they scooped, hauled, and composted 20,000 pounds of urchins. Some innovative conservationists also have been removing emaciated urchins to onshore tanks to fatten them up for humans to eat.

- The dire kelp situation is an expression of catastrophic tipping points and ecosystem shifts that climate change can bring. The collapse of Northern California’s kelp forests was quick and nearly total. Meanwhile, marine heatwaves are increasing in intensity and frequency, making the long-term recovery of kelp forests uncertain.

- Yet there are some hopeful signs. Closer to Alaska, sunflower sea stars are starting to recover. Near Monterey Bay, urchin-eating sea otters have been able to protect local kelp forests. And in spring 2021, Reef Check reported new bull kelp growing at one of the surviving patches off the Mendocino coast.

- Freely availability satellite data can provide insights about the environmental drivers influencing kelp productivity, potentially helping managers time their restoration efforts for years when conditions will best support kelp growth, McPherson explained. “Landsat has allowed managers to observe regional trends in kelp canopy area and biomass across more than 30 years,” she said. “This is very valuable.”

• June 2, 2021: Ghana is one of the leading producers of gold in Africa and the seventh leading producer in the world. Large commercial companies mine the majority of it using heavy machinery. But about 35 percent is extracted through small-scale mines, many of which operate informally or without a valid license. ⁴⁰⁾

- This unregulated small-scale and artisanal gold mining is known locally as galamsey, a slang word derived from the Ghanaian words “gather” and “sell.” About one million Ghanaians engage in the practice, supporting about 4.5 million people in the country. Many of the galamseyers live in poverty, and their activities often come at a cost to both human health and the environment.

- Although individual galamsey sites cover less area than an industrial mine, their cumulative effect on the landscape outweighs those of larger mines. In the southwestern forests of Ghana, for instance, the footprint of small-scale mines is nearly seven times greater than that of industrial mines. The mercury and heavy metals used in galamsey can contaminate drinking water for entire communities. It also causes major health issues, such as kidney problems and neurological disorders, to those continually exposed to the metals.

​

​​

​

​​

- “Local authorities may have knowledge about a specific area, but if the mines are scattered all over the place, then they are difficult to find,” said Foster Mensah, executive director at the Center for Remote Sensing and Geographic Information Services (CERSGIS) in Ghana. “The maps and products we can generate through satellite imagery help them see areas that need attention and intervention.”

- Mensah and colleagues at CERSGIS have been working with the SERVIR-West Africa program to identify and quantify mining activities in highly forested areas, which are mostly located in southern Ghana. SERVIR-West Africa is a program between NASA and the U.S. Agency for International Development (USAID) that uses remote sensing to provide support for protection of food and water resources and sustainable development.

- Mensah’s team uses radar data from the European Space Agency’s Sentinel satellites, which can penetrate clouds to see the ground activities below. The team also uses Landsat data to decipher long-term changes in forest coverage and degradation. The visualization at the top of this page shows mining activities from 2015-2020 in southern Ghana. As of 2018, galamsey had led to about 29,000 hectares (72,000 acres) of deforestation, with 1,000 hectares (2,600 acres) occurring in protected areas of the country.

- “It can be hard to distinguish between illegal mining and legal mining in an area,” said Mary Amponsah, also a researcher with CERSGIS and SERVIR-West Africa. “When you look at the maps, most illegal activity sits close to legal mining concessions.”

- When the government grants legal mining concessions to large companies, Amponsah noted, galamseyers explore the surrounding areas for other places to mine. However, they may not have a license or they may be mining in unauthorized or protected areas. Some license holders also mine more area than allowed.

- Together with the non-governmental organization A Rocha Ghana, the CERSGIS and SERVIR teams have met with community leaders and showed how galmasey is affecting the landscape and resources. They demonstrated a mobile app that allows anyone to report illegal mining that they see. The satellite data and the crowdsourced information are stored on a web-based portal that the public can access.

- The team has also been working with Ghana’s Environmental Protection Agency and its Forestry Commission to highlight areas where mining is affecting forest coverage and degradation. For closed or abandoned mines, the team is also using the satellite data to help inform reclamation projects. Knowing the location and extent of degraded forests can help land managers better project the labor and expense to reclaim an area (by planting tree seedlings or adding plants that could detoxify the area, for instance).

- “It boils down to providing authorities information and data they did not have before, especially over a wide area,” said Mensah. “The satellite data is cost effective and gives them a head start on how to pinpoint mining hot spots that need immediate attention.”

​

​​

• May 31, 2021: Most asteroids that survive an encounter with Earth’s atmosphere ultimately plummet into water, simply because oceans cover 70 percent of the planet. But massive space rocks occasionally hit land. That was the case 50,000 years ago when an iron asteroid smashed into North America and left a gaping hole in what is today northern Arizona. ⁴¹⁾

​

​​

- Even at 50,000 years old, the crater is relatively young and remarkably well-preserved compared to other craters. Because of this, scientists have studied the site extensively to learn about cratering processes—how they work on Earth and elsewhere in the solar system—and about the modern hazards posed by asteroid impacts.

- “A similar-size impact event today could destroy a city the size of Kansas City,” said David Kring, an impact cratering expert at the Lunar and Planetary Institute. Meteor Crater measures 0.75 miles (1.2 km) across and about 600 feet (180 m) deep. The size of the asteroid that produced the impact is uncertain—likely in the range of 100 to 170 feet (30 to 50 meters) across—but it had to be large enough to excavate 175 million metric tons of rock.

- The wide perspective pictured above gives a sense of the crater in context with the surrounding area. This part of the Colorado Plateau drains from Anderson Mesa (lower left) and across a surface that dips toward the Little Colorado River near Winslow. The red blotchy areas near the crater are Moenkopi red siltstone amid light-brown Kaibab limestone. Volcanic landforms dot part of the wider landscape, including Anderson Mesa and the West and East Sunset Mountains.

- Note how the crater’s rim and areas just outside it are much lighter tan. This is the debris that was ejected from the crater, consisting primarily of Kaibab limestone and Coconino sandstone. Also notice how the crater is not exactly circular, exhibiting almost a square shape. According to Kring, this is because pre-existing flaws in the rock caused it to peel back farther in four directions upon impact. These cracks, oriented northwest-southeast and northeast-southwest, formed when the Colorado Plateau was uplifted from below sea level to its current mile-high elevation.

- The landscape has not always looked like this. When the asteroid hit, humans had not yet reached North America. The terrain of forested rolling hills was likely inhabited by mammoths, mastodons, and giant ground sloths. Now the crater stands amid shrub-covered desert.

- Kring continues to host a NASA-sponsored field training and research program at Meteor Crater, in which graduate students train to study impact craters on Earth, the Moon, Mars, and other planets. He also trains astronauts “so they are familiar with impact-cratered planetary surfaces,“ Kring said. “NASA’s Artemis astronauts will, for example, be landing in an impact-cratered terrain around the lunar south pole.”

• May 29, 2021: Strong northwesterly winds routinely blow down the eastern side of the Andes Mountains and whip across the central Patagonia Desert. In the process, they lift abundant dust from Argentina’s Lake Colhué Huapi, making it the largest and most active source of dust storms in the region. ⁴²⁾

​

​​

- While dust storms are common here, scientists are only beginning to track them rigorously and research the role they play in the regional environment. Colhué Huapi dust likely affects the region in several ways, explained NASA remote sensing scientist Santiago Gassó. Field research and ice cores suggest that winds may transport Colhué Huapi dust as far as East Antarctica, where it could have consequences for how quickly snow and ice melts. The dust storms also may be a significant fertilizer for the South Atlantic Ocean, providing key minerals that may trigger blooms of phytoplankton.

- To better understand the role of Colhué Huapi dust storms, Gassó recently analyzed satellite and surface weather data from the past five decades, assessing the year-to-year variability in dust storms and identifying periods of high activity. Dust storms peak during the summer (December through March), though wintertime events (May through August) are also common, Gassó found. Most years brought 15 to 30 moderate to large events. There has also been steady increase in the number of dusty days observed since the 1970s, according to his analysis.

- “Events like these are a reminder that dust activity is not just a warm weather phenomenon,” said Gassó. “It can happen in cold places, too. You just need loose soil, limited moisture, and winds.”

• May 28, 2021: Point Roberts, Washington, is like many small coastal towns in the Pacific Northwest, with access to epic places to fish, hike on the beach, and watch whales. But unlike other coastal towns, getting to Point Roberts is a bit more complicated. To drive there from mainland Washington, you must cross an international border twice. ⁴³⁾

​

​​

- The wide view shows Point Roberts dangling below the 49th parallel—the line of latitude that was established in 1846 as the political boundary between the northwestern United States and Canada. Point Roberts is further isolated by the Strait of Georgia to the west and south and Boundary Bay to the east. The image of Figure 89 shows a detailed view of Tsawwassen peninsula and Point Roberts.

​

​​

- Political boundaries can sometimes affect built landscapes in ways that are visible from space. In this case, the green expanse of the Bald Eagle Golf Club abruptly ends south of the border; just north of the border in Canada, the geometric patterns of the suburban community of Tsawwassen take shape.

- Point Roberts is a popular vacation spot for Canadians, which helps drive the town’s economy. Since the closing of the U.S.-Canada border in mid-March 2020 due to COVID-19, news reports have likened it to a ghost town in the making. The closure put a halt to routine border crossings to mainland Washington—just 25 miles away—temporarily ending previously routine trips by the town’s residents to schools and medical care.

- The ferry terminal visible in these images connects two Canadian points—the town of Tsawwassen and Vancouver Island. For now, emergency ferry service is available as necessary from the Point Roberts marina to Bellingham, Washington. At the time of this story, the border was expected to remain closed until at least June 21, 2021.

- Some natural features are unaffected by political borders. Notice, for example, the striking plume streaming from the mouth of the Fraser, the longest river in British Columbia. The river carries about 20 million tons of silt each year, much of it into the Strait of Georgia. Moved around by winds, currents, and tides, the silt provides nutrients that fertilize the region’s waters and support its salmon populations, which in turn make Point Roberts a great place to view the local pods of orcas.

• May 21, 2021: Zombie fires, holdover fires, hibernating fires, or overwintering fires: Whatever you choose to call them, you’re probably going to hear a lot more about them in the coming years. New research shows that this type of wildfire—which can survive the snow and rain of winter to re-emerge in spring—is becoming more common in high northern latitudes as the climate warms. ⁴⁴⁾

- “Smoldering fires are flaming fires that have entered ‘energy-saver mode,’” said Rebecca Scholten of Vrije Universiteit Amsterdam. The fires start above ground, then continue to smolder in the soil or under tree roots through winter. “These fires are only just surviving based on the resources they have—oxygen and fuel—and can transition back into flaming fires once conditions are more favorable.”

​

​​

​

​​

- The incident was not an isolated case. The study points to numerous fires that overwintered after Alaska’s large fire years of 2009 and 2015, although they can happen after other hot and active fire years, too.

- “Although our satellite record of these fires in itself is too short to look at long-term trends, we found that the number of fires that overwinter is strongly linked to summer temperatures and large fire seasons,” Scholten said. “And for these we do see a pronounced upward trend—hotter summers and more burned area—with continued climate warming.”