January 27th, 2021 by Kathryn Hansen/NASA Earth Observatory, and Robie Macdonald/University of Manitoba/Dept. of Fisheries and Oceans
In a typical year, perhaps a dozen people visit Auluvik National Park in Canada’s Northwest Territories. Luckily, one of those visitors brought back some outstanding photos.
In November 2020, we highlighted a few compelling features around the Thomsen River estuary on Banks Island, including lines of sea ice tracing the shoreline and the braided pattern of the river. But there’s so much more to explore across this remote lowland tundra and river valley.
Robie Macdonald, a scientist at the University of Manitoba, shared some photos that he shot while doing fieldwork in the region between 2014 and 2016. The purpose of that project, led by Matt Alkire of the University of Washington, was to collect geochemical measurements from small rivers across the Canadian Arctic Archipelago.
“I really do love working in these places,” Macdonald said. “Once the aircraft has landed, one is bathed in a tremendous silence broken only by waves breaking on shingle. Then you have this incredible tundra spreading out toward the hills that define the river floodplain.”
Here are ten of Macdonald’s favorite photographs.
1. Ponds and Oxbows
“Numerous ponds of all sizes populate the drainage basins of Banks Island, and you can see several clusters of them in the satellite image (top), especially along the small river to the west of the Thomsen. This photograph provides a closer look at one such pond cluster. In the image, you can also see textbook oxbows, which have become the setting for more ponds.”
2. Permafrost Polygons
“During breeding season, it seems like almost every pond on Banks Island has its own population of snow geese (visible in this photo). You can also see old permafrost polygons that are now submerged within the pond. Polygons are widespread features of the permafrost in soil-rich locations and are produced over time by freeze-thaw cycles of the surface active layer. Permafrost thaw is widely impacting these regions, leading to feedbacks in the carbon system (CO2, CH4).”
3. Vibrant Vegetation
“Perhaps the most surprising characteristic of the valley bottoms in this ‘Arctic desert’ is the vibrant color of the vegetation: yellows, greens, and reds mark a dense ground cover that can be seen on the satellite image as areas with a yellowish-brownish cast.”
4. Sediment Ripples
“As a result of the strong sediment supply, the large embayment at the Thomsen River mouth has been practically filled with sediment. The shallow water reveals itself in the satellite image by the lighter-greenish tone compared to water out in the channel north of Banks Island. More evidence of the ample sediment supply can be seen in beautiful displays of sand/silt ripples in the lower river between the islands. In the satellite image (top), the ripples are almost visible as grey zones between the islands before the river enters the open bay.”
5. Ice Shoves
“When walking on these islands near the river mouth, you can see evidence of bank erosion and ‘ice shoves.’ These are produced when wind forces newly formed ice to ride up over the river bank and gouge out the top layer of the silty material that makes up these islands. Unfortunately, ice shoves are too small to show on the satellite image.”
6. Vulnerable Permafrost
“Global warming and the extensive loss of sea-ice cover in late summer have helped accelerate coastal erosion and permafrost slumping. This image shows a section of coastline just to the east of the Thomsen River mouth that consists of a lot of frozen ice. This sort of permafrost is especially vulnerable to the changing temperature regime.”
7. Erosion and Slumping
“Thaw slumps are also a sign of the permafrost warming. These can be seen just barely in the satellite image as small dark regions along cliff faces–both facing the ocean and within the river drainage basins. Erosion and slumping expose ancient organic carbon to the air and the hydrosphere, thus providing an extensive positive feedback to climate warming.”
8. Bergy Bits
“Lines of bergy bits has collected along a thin shore margin at the point where the sea bottom rapidly deepens below ice keel depths, likely at approximately 2-4 meters. Although the grounded ice bits are continually melting, they are resupplied by more ice chunks shed from the permanent pack out in the channel. Two turbid plumes supplied by a river to the west of the Thomsen easily pass through the necklace of ice.”
9. Sampling Amid an Icy Barrier
“When we were sampling the water in this region, we found this ice barrier to be a bit more of a problem to navigate in our small inflatable boats, but ice along the shore did make it simple to sample sea ice. This image shows Greg Lehn preparing to launch our boat.”
10. A Suitable Landing Spot
Sampling in the Thomson River itself was somewhat simpler, once we had found a suitable place to land the plane. This image shows Greg Lehn scoping out the shore of the Thomsen River near its mouth.”
Every month on Earth Matters, we offer a puzzling satellite image. The November 2020 puzzler is above. Your challenge is to use the comments section to tell us what we are looking at, where it is, and why it is interesting.
How to answer. You can use a few words or several paragraphs. You might simply tell us the location, or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure feature. If you think something is interesting or noteworthy, tell us about it.
The prize. We cannot offer prize money or a trip to Mars, but we can promise you credit and glory. Well, maybe just credit. A few days after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. After we post the answer, we will acknowledge the first person to correctly identify the image at the bottom of this blog post. We also may recognize readers who offer the most interesting tidbits of information about the geological, meteorological, or human processes that have shaped the landscape. Please include your preferred name or alias with your comment. If you work for or attend an institution that you would like to recognize, please mention that as well.
Recent winners. If you’ve won the puzzler in the past few months, or if you work in geospatial imaging, please hold your answer for at least a day to give less experienced readers a chance.
Releasing Comments. Savvy readers have solved some puzzlers after a few minutes. To give more people a chance, we may wait 24 to 48 hours before posting comments. Good luck!
UPDATE on November 9 — The answer is a phytoplankton bloom near the Jason Islands, an archipelago off of the Falkland (Malvinas) Islands. Read more about it here.Evzen Schulc quickly identified that it was an ocean bloom, though no one managed to identify the location.
For the second year in a row, fierce fires have burned throughout Bolivia. They are the product of a prolonged drought, which has supercharged the fires that are lit seasonally by farmers and ranchers to maintain grazing land and to clear forest and woodlands for agricultural production.
But not all the red dots on the map are of equal ecological significance. As these screenshots (below) from NASA’s Amazon fire dashboard make clear, there is a lot of variety in the types of fires that have burned in Bolivia in recent months, and they vary by region and ecosystem.
Many fires in the region are short-lived grassland and savanna fires; these burn vegetation that regrows quickly, and there is usually little ecological damage and minimal carbon emissions. Likewise, many others are small-scale land clearing and agricultural fires that do not cause substantial new damage to intact tropical forests.
On the other hand, some of those red dots are long-lasting, intense deforestation fires that were lit specifically to burn trees as part of land-clearing processes. These fires turn patches of tropical forests into pasture or cropland, fragmenting the remaining forests and altering ecosystems for decades.
Others are low-intensity understory fires that typically begin in cleared areas as agricultural fires, but then escape into neighboring forests. Even a low-intensity fire may kill half of the trees, unleashing a cascade of ecological changes that can transform tropical forests into open-canopy woodlands over time.
The charts above highlight the types and trends of fire type for three states (departments) in Bolivia. The northerly Pando department is still dominated by intact tropical rainforest. Satellites have detected large numbers of deforestation and agricultural fires burning there since August 2020, particularly along Highway 13. With more grasslands and fewer forests, El Beni has a higher proportion of the less-damaging fire types. The large Santa Cruz department, home to the Chiquitano dry forest and Pantanal grasslands, has comparatively large numbers of understory and grass fires.
“The goal of our new classification system is to provide real-time information on what types of fires are burning across the Amazon region every day. With thousands of individual fires burning at this point in the dry season, the question is how to prioritize regional efforts for fire suppression to best protect communities and ecosystems. Understory fires are particularly devastating in Amazon forests that are not adapted to fire,” said Douglas Morton, chief of the Biospheric Sciences Laboratory at NASA’s Goddard Space Flight Center. “However, it is worth pointing out that our real-time classification system for Amazon fires is not the only way of categorizing fires. We are working closely with state and national agencies across the Amazon to improve the classification, based on feedback from field crews.”
EO Kids – Come Explore Earth with EO Kids! Read all about different topics in NASA Earth science and try out the hands-on activities. Each issue helps students learn how NASA’s fleet of satellites help us understand and plan for our changing world. Issues are available as printable PDFs. Educators can print and distribute to students with limited access to technology. Parents can print issues for their children so they can actively learn while taking a break from screen-time.
For students on computers, check out EO Kids videos of some of the cool activities featured in our issues. At EO Kids we are committed to making Earth science fun and engaging. Come explore our Earth with us!
Mission: Biomes – In celebration of 20 years since its first release, the Earth Observatory has updated the Mission: Biomes activity to support interactive learning and awareness of seven terrestrial biomes: rainforest, grassland, temperate deciduous forest, coniferous forest, desert, tundra, and shrubland. After reading about each biome, users can enter “The Great Graph Match” and test their biome knowledge. After mastering “The Great Graph Match”, users can enter the “To Plant or Not to Plant?” mission, read about 19 plants growing all over the world, and match those plants to the biome they prefer. Visit the Teacher Resources page to learn more about the Mission: Biomes goals, expected outcomes for students, the Next Generation Science Standards alignment, general tips for navigating the site, additional activities to learn, and more!
Earth, a photo essay – NASA’s Earth is a fantastic resource for students to practice their reading skills while learning about Earth through stunning images of our planet. Through this book students appreciate science as art, part of STEAM (Science, Technology, Engineering, Art, and Math) focused curriculums.
The Earth Observatory team hopes that you all have an inspiring and informative school year!
Every time we run one of these tournaments, we are surprised by what catches the eyes of our readers. It is time to surprise us again. Cast your votes now in round three to pick the best four of the Earthly 8. Voting ends on April 13 at 9 a.m. U.S. Eastern Time. Check out the remaining competitors below.
“Past Winners” Bracket: Ocean Sand, Bahamas (#5) vs. A View of Earth from Saturn (#2)
Fire in the Sky and On the Ground has pulled off two massive upsets. In round 1, it beat #2 seed Night Light Maps Open Up New Applications, 71 to 29 percent. In round 2, Fire beat the sentimental favorite and oldest image in Tournament Earth, All of You on the Good Earth — the original Blue Marble photo (1968) and the inspiration for the first Earth Day (1970). The voters chose the auroral fire over Apollo 8 fame by 57 to 43 percent.
“Ice and Land” Bracket: Where the Dunes End (#8) vs. Retreat of the Columbia Glacier (#6)
It has been a tough month on Earth. Good news has been scarce. But here’s at least one update ― from one million miles away ― to appreciate.
The Deep Space Climate Observatory (DSCOVR) satellite, which had been out of commission for about nine months due to a technical problem, is fully operational again, according to NOAA. Issues with the satellite’s attitude control system prompted engineers to put the satellite into a “safe hold” in June 2019, but they recently developed a software fix for the problem.
And that means that the satellite’s Earth Polychromatic Imaging Camera (EPIC) is once again taking beautiful full-disk images of our home several times each day. NASA’s EPIC instrument acquired the image of Africa and Europe (above) on March 19, 2020.
Head over to the science team page for EPIC and take a few moments to savor some imagery of our ever-changing planet. If Twitter is more your style, check out @DSCOVRDaily. Look carefully and you’ll see clouds and storm fronts coming and going, plumes of dust or smoke rising and fading, and whole continents greening and browning as the seasons change.
“[One of the] conclusions they draw is that we are really all in this together,” he said. “Our fate is bound up with people that we may think are really different from [us]. We may have different religions, we may have different politics. But ultimately, we are connected. Totally connected.”
The video below, based on photographs taken by GLOBE citizen scientist Glenn Evans, juxtaposes satellite images and photographs taken of the sky at roughly the same place and time. The contrasting perspectives underscore how easy it can be to miss the forest for the trees — or, rather, the smoke plume for the clouds — if you aren’t careful. Kristen Weaver, the deputy coordinator for GLOBE Observer, compiled the photos and matched them with the corresponding MODIS satellite images.
Victoria and New South Wales are in the midst of one of the most severe fire seasons either state has seen in decades. After months of unusually hot, dry weather, hundreds of fires have charred an area larger than West Virginia, destroying thousands of homes and resulting in dozens of deaths.
More than 20 years ago, NASA scientist Ralph Kahn authored a column for the Los Angeles Times anticipating the launch of a new satellite — and ultimately a whole fleet of satellites — that would study Earth.
“We want a picture of Earth that is more specific about what is happening to the climate, which after all is what makes the planet habitable,” he wrote. And that picture needed to be rich with detail. “Precisely where are deserts encroaching on grasslands? In what regions is it raining more than usual? Exactly how much are glaciers shrinking, and at what rate is the sea level rising?” he asked.
“About every seven weeks, the satellite archives will receive as much data from EOS-AM as are held in all the volumes of the Library of Congress. And the EOS-AM satellite alone is supposed to keep pouring numbers down from the sky, relentlessly, for at least six years,” Kahn wrote.
Amazingly, all those numbers from Terra continue to pour down 20 years later. Over time, the flood of data from Terra and several other satellites has turned into scientific discoveries. Bit by bit, the questions Kahn initially posed in his column have been answered.
In November 2019, we highlighted this Landsat 8 image showing a glut of sediment flowing down the Susquehanna River into Chesapeake Bay. It was a striking, timely image, but one of the realities of publishing new content every day is that sometimes good information comes in after a deadline has passed.
In this case, Mark Trice, a water quality expert with the Maryland Department of Natural Resources, pointed out a few things about Susquehanna sediment after our story was out that seem worth passing on.
Among them: a link to a recent report that synthesizes and summarizes what scientists have learned about the ecological effects of high sediment flows on the Susquehanna River and the role of the Conowingo Dam. While the dam trapped most sediment and associated nutrient pollution (nitrogen and phosphorus) when it was first built, enough material has piled up behind the dam now that significant amounts of sediment and nutrients now flow past it during storms. A University of Maryland press release summarized the findings this way:
Most sediment and particulate nutrient impacts to the Bay occur during high-flow events, such as during major storms, which occur less than 10 percent of the time. Loads delivered to the upper Chesapeake Bay during low flows have decreased since the late 1970s, while loads during large storm events have increased. Most of these materials are retained within the upper Bay but some can be transported to the mid-Bay during major storm events, where their nutrients could become bioavailable.
The potential impact of reservoir sediments to Bay water quality are limited due to the low reactivity of scoured material, which decreases the impact of total nutrient loading even in extreme storms. Most of this material would deposit in the low salinity waters of the upper Bay, where rates of nitrogen and phosphorus release from sediments into the water are low.
“While storm events can have major short-term impacts, the Bay is actually really resilient, which is remarkable,” said the study’s lead author Cindy Palinkas, associate professor at the University of Maryland Center for Environmental Science. “If we are doing all of the right things, it can handle the occasional big input of sediment.”
Trice’s colleagues at the Maryland Department of Natural Resources (DNR) underscored the Bay’s resiliency to sediment as well when I asked about the recent event. “Although these high flow events routinely occur, the Bay is resilient and continues to show improvement due to the commitment by the Bay watershed partners to have all pollution reduction strategies implemented by 2025 to have a healthy Chesapeake Bay,” said Bruce Michael of Maryland DNR.
Also worth mentioning: the 2019 water year (October 1, 2018, to September 30, 2019) brought a record-breaking flow of freshwater into the Bay, Trice noted. “The annual average freshwater flow into the Chesapeake Bay during water year 2019 was 130,750 cubic feet per second, which is the highest annual amount since 1937, the first year for which data are available,” the U.S Geological Survey said.
Finally, thank you to Virginia Tech geology professor Brian Romans (@clasticdetritus) for pointing out something about the image that is unrelated to sediment but fascinating: the line of cities and suburbs running from Baltimore, Md., to Richmond, Va., marks the boundary between two key geologic zones: the flat Coastal Plain to the east and the more rugged Piedmont to the west. Interestingly, many cities are located along this “fall line” because rapids prevented boats from traveling any farther upstream when they were first settled.
June 18th, 2019 by Laura Rocchio, Landsat Communication and Public Engagement Team
The UK’s Antarctic Place-names Committee has agreed that seven ice features in western Antarctica should be named for Earth-observation satellites. One of them is Landsat Ice Steam.
The new designations were announced on June 7, 2019. The ice features are all located in Western Palmer Land on the southern Antarctic Peninsula.
The seven features ring George VI Sound like pearls on a necklace. The new names, as officially entered into the British Antarctic Territory Gazetteer, are (from west to east): Landsat Ice Steam, ALOS Ice Rumples, Sentinel Ice Stream, GRACE Ice Stream, Envisat Ice Stream, Cryosat Ice Stream, and ERS Ice Stream.
The UK has submitted the new names for the fast-moving ice features to Scientific Committee on Antarctic Research (SCAR), which maintains a gazetteer or registry, of names officially adopted by individual nations. Under the Antarctic Treaty, signatory nations confer on geographic feature names, but each nation’s naming authority formally adopts new names. The U.S. Board on Geographic Names will meet in July and may discuss at that meeting whether the names adopted by the UK also will be adopted by the US. The question of using the term “glacier” for the ice features instead of “ice stream” is also part of each nation’s naming decision.
The new names were proposed by Anna Hogg, a glaciologist with the Center for Polar Observation and Modelling at the University of Leeds. In research published in 2017, Hogg found that glaciers draining from the Antarctic Peninsula were accelerating, thinning, and retreating, with implications for global sea level rise. The fast-moving glaciers that Hogg and colleagues tracked with radar and optical satellite imagery were unnamed. In her paper, the glaciers had to be designated by latitude and longitude.
Satellites had enabled Hogg and her team to clock the speed of these nameless ice features—some with rates faster than 1.5 meters/day. In tribute to the spaceborne instruments, Hogg came up with a way to describe the fast-moving ice features more succinctly—name them after the satellites that had helped her understand their behavior.
Hogg proposed to the U.K.’s Antarctic Place-names Committee that the features should be named for Landsat, Sentinel, ALOS PALSAR, ERS, GRACE, CryoSat, and Envisat. She was notified in early June that the committee had agreed to adopt the names, which provide a way to recognize international collaboration, as fifteen space agencies currently collaborate on Antarctic data collection.
“Satellites are the heroes in my science of glaciology,” Hogg told the BBC. “They’ve totally revolutionized our understanding, and I thought it would be brilliant to commemorate them in this way.”
Naming the glaciers after satellites is also a celebration of data fusion. “Our understanding of ice velocities and ice sheet mass balance has come from putting many different remote sensing data sets together—optical, radar, gravity, and laser altimetry,” said Jeff Masek, the NASA Landsat 9 Project Scientist. “Landsat has been a key piece in assembling that larger puzzle. Naming an ice stream after Landsat is a fitting way to recognize the value of long-term Earth Observation data for measuring changes in Earth’ polar regions.”
Read more from NASA’s Landsat science and outreach team, including the history of Antarctic observation with Landsat. Read more about all of the glaciers and their namesake satellites, as told by the European Space Agency. And read about the island discovered by and named for Landsat, and the woman who discovered it.
Correction, June 27, 2019: SCAR’s role in the Antarctic naming process was incorrectly described in the earlier version of this article. Updates were provided by Dr. Scott Borg, Deputy Assistant Director of the National Science Foundation’s Directorate for Geosciences, and Peter West, the Outreach Program managers for NSF’s Office of Polar Programs, to correctly describe the naming process.