Earth Matters

Kīlauea’s Summit Lake: Still Rising

October 9th, 2020 by Adam Voiland
Image Credit: NASA Earth Observatory
Data Credit: U.S. Geological Survey

In May 2020, we published a story about a new lake growing in the summit caldera of Hawaii’s Kīlauea volcano. Six months later, the heated lake continues to rise. The water level now tops 40 meters (130 feet), according to U.S Geological Survey (USGS) measurements made with a laser rangefinder.

Though gentle “effusive” eruptions have been the norm at Kīlauea across the past two centuries, the geologic record shows plenty of evidence that the volcano has had periods when violent, explosive eruptions were common. The presence of water in magma is a key factor contributing to explosive eruptions, so USGS scientists have been carefully monitoring the volcano for signs that it may be entering a more explosive and dangerous phase.

As detailed in a September 2020 EOS article, that monitoring has included sending unoccupied aircraft systems (UAS)—drones—deep into the crater to get a closer look at the lake. Scientists have also been conducting regular helicopter flights over the lake and monitoring a suite of ground-based sensors (seismometers, GPS sites, thermal cameras, and others) that measure the motion of the ground, gaseous emissions, and the appearance and temperature of the lake.

Credit: U.S. Geological Survey by photo M. Patrick.

Meanwhile, satellites provide the big-picture view. Landsat satellites periodically collect multi-spectral imagery of the lake; the images at the top of this page provide a natural-color perspective. Other satellites with Interferometric Aperture Radar (InSAR) complement the ground-based GPS sites by offering a crucial, large-scale view of land deformation.

“The chance to monitor an incipient volcanic lake is not unprecedented, but it is rare,” a group of USGS geologists wrote in EOS. “Kīlauea’s crater lake provides an opportunity to improve the scientific community’s understanding of how such lakes evolve and interact with magmatic systems below.”

Credit: U. S. Geological Survey photo by M. Patrick

One byproduct of all the scientific monitoring is a steady stream of lake imagery that is visually striking as well as scientifically interesting. In July, for instance, morning sunglint transformed the muddy brown water to something that glittered and shimmered (see photo above). Influxes of new water often set up gradients of color that range from green to rusty orange (also above). And on a day when a light mist moved across the caldera, a webcam at the summit acquired a striking image of a rainbow framing the lake (below). You can find more images in Hawaii Volcano Observatory’s photo and video chronology.

Credit: U. S. Geological Survey

September Puzzler

September 29th, 2020 by Kasha Patel

Every month on Earth Matters, we offer a puzzling satellite image. The September 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. Roughly one week 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!

See our “Sandy Plains in the Arctic” Image of the Day for the answer.

Welcome back to school!

September 9th, 2020 by Andi Brinn Thomas

School is starting and NASA’s Earth Observatory has resources for children and teachers!
EO kids logo

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 activity logo

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 book cover/ logo

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!

Hurricane Resources for an Active Atlantic Season

August 31st, 2020 by Andi Brinn Thomas

The 2020 Atlantic Hurricane season, which runs from June 1 to November 30, is off to an extremely active start. For the first time in modern history, nine named storms formed in the basin before August 1. (The historical average is two storms before August 1.) The National Hurricane Center predicted 19 to 25 named Atlantic storms in 2020, with 7 to 11 of those storms strong enough to be classified as hurricanes.

Hurricane Laura and Hurricane Marco making landfall on August 24, 2020.
Hurricane Laura and Hurricane Marco making their way to the U.S. Gulf Coast on August 24, 2020.

Accessing NASA data to track and research these events can sometimes feel like a maze. For a comprehensive starting point, Earthdata has a new Cyclones Data Pathfinder summarizing the data available for pre-assessing storms, making near real-time assessments, and conducting post-storm analysis. There is clear information on where to find and easily visualize those datasets.

In addition, you will find an article in the “Learn” section of Earthdata that covers the improvements made to hurricane forecasts and near real-time observations in recent years and what future NASA missions might bring to the study of tropical storms. It also examines some different satellite observations that can contribute to better forecasting, such as sea surface temperatures (SST) and soil moisture measurements.

For the developers, the Earth Observatory Natural Event Tracker (EONET) can be used to monitor tropical storms through an API that provides up-to-date metadata for a variety of curated natural events. Use the How-to Guide to find out more about how EONET can be used to track storms.

August Puzzler

August 25th, 2020 by Adam Voiland

Every month on Earth Matters, we offer a puzzling satellite image. The August 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. Roughly one week 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!

Editor’s Note: Read La Malinche’s Barrancas for the answer.

July Puzzler

July 28th, 2020 by Adam Voiland

Every month on Earth Matters, we offer a puzzling satellite image. The July 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. Roughly one week 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!

See our “Cultivating Ideas for Mars” Image of the Day for the answer.

June Puzzler

June 30th, 2020 by Kathryn Hansen



Every month on Earth Matters, we offer a puzzling satellite image. The June 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. Roughly one week 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!


Acertijo de Junio

Cada mes en la sección Earth Matters, ofrecemos una imagen de satélite intrigante. La imagen superior es el acertijo de junio 2020. Tu desafío es usar la sección de comentarios para decirnos qué miramos, dónde está, y por qué es interesante.

Cómo participar. Responde usando unas pocas palabras o varios párrafos. Puedes solo darnos la ubicación, o puedes profundizar y explicar qué satélite e instrumento produjeron la imagen, qué bandas espectrales se emplearon para crearla, o qué resulta atractivo en algún elemento poco definido. Si piensas que algo es interesante o digno de mención, dínoslo.

El premio. No podemos ofrecerte recompensa monetaria o un viaje a Marte, pero podemos prometerte reconocimiento y fama. En verdad, solo reconocimiento. Aproximadamente una semana después de publicar la imagen acertijo en este blog, publicaremos una versión comentada y subtitulada como nuestra imagen del día. Tras publicar la respuesta, daremos crédito a la primera persona que identificó correctamente la imagen en la parte inferior de la publicación. También podemos dar crédito a los participantes que ofrecieron las piezas de información más interesantes sobre los procesos geológicos, meteorológicos, o humanos que dieron forma al paisaje. Por favor incluye tu nombre o alias con tu comentario. Si trabajas o asistes a una institución que quieras reconocer, por favor menciónala también.

Ganadores recientes. Si has ganado uno de los acertijos de los últimos meses, o si trabajas con imágenes geoespaciales, por favor contén tu respuesta por al menos un día para dar oportunidad a aquellos lectores menos experimentados.

Publicación de comentarios.Los lectores expertos han resuelto algunos de los acertijos en solo minutos. Para dar oportunidad de resolverlo a la mayor cantidad de lectores, la publicación de comentarios puede retardarse de 24 a 48 horas. ¡Buena suerte!

Esta entrada fue originalmente publicada el martes, 30 de junio de 2020 a las 3:00 pm y está archivada bajo la sección EO Satellite Puzzler. Puedes hacer seguimiento a las respuestas de este acertijo a través de la fuente RSS 2.0. Puedes saltar hasta el final y dejar una respuesta. Actualmente no está permitido hacer ping.

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NASA, ESA, and JAXA Provide Global Observations of COVID-19 Impacts

June 29th, 2020 by Emily Cassidy, NASA Earth Science Data Systems

NASA, the European Space Agency (ESA), and the Japan Aerospace Exploration Agency (JAXA) have joined forces to create the COVID-19 Earth Observation Dashboard. The web platform combines the collective scientific power of the agencies’ Earth-observing satellites to document changes in the environment and society in response to the pandemic. 

The dashboard is a user-friendly tool to track changes in air and water quality, climate change, economic activity, and agriculture.

Average nitrogen dioxide (NO2) concentrations are shown from March 13 to April 13, 2020.
Average nitrogen dioxide (NO2) concentrations over Europe are shown from March 13 to April 13, 2020, compared to the same time in 2019. Image courtesy of ESA.

Air quality changes were among the first noticeable impacts of pandemic-related stay-at-home orders, and the resulting reductions in industrial activity, that could be tracked through satellite observations. Reductions in nitrogen dioxide (NO2) levels — primarily related to temporary reductions in the burning of fossil fuels — show up clearly in satellite data. 

A preliminary analysis also indicates that planting (farming) activity dropped during the quarantines and lockdowns. For example, the cultivated area of white asparagus in Brandenburg, Germany, has been 20 to 30 percent lower this year, compared to 2019. More information on agricultural productivity changes will be added to the dashboard in the months to come.

NASA, ESA, and JAXA have assembled a wide array of satellite observations for the COVID-19 dashboard, including data on nighttime lights from the NASA-NOAA Suomi NPP satellite. This image shows San Francisco Bay. Image courtesy of the Black Marble team.

Recent water quality changes have been reported in a few locations that typically have intense industry and tourism — activities that have decreased during the pandemic. Data on ship identification, construction activity, and nighttime lights (above) are featured on the dashboard to keep track of some of the economic ramifications of the virus. 

Together, ESA, JAXA, and NASA will continue to add new observations to the dashboard in the coming months to see how these indicators change. Learn more in the NASA press release, the video below, or by exploring the dashboard

A series of research papers in recent months shows that we know more than ever before about the ice on our land and covering the seas. In case you missed them, here’s a look at some of the notable findings. Many are based on data from NASA’s ICESat-2 satellite, which just over a year ago released to the public more than a trillion new measurements of Earth’s height. With these and other satellite data scientists have …

… Produced the First Satellite-Based Maps of Snow Depth on Sea Ice

Earlier this month we wrote about how the data were used to make the first maps of snow depth on sea ice. The research, published in JGR Oceans, shows how elevation measurements from ICESat-2 can be combined with data from ESA’s Cryosat-2 to get maps like these:

The snow layer is an important component of the sea ice system, affecting how the ice cover grows and melts. With additional years of observations, such maps could help scientists assess how climate change affects precipitation and the accumulation of snow. 

… Estimated the Thinning of Arctic Sea Ice

In another paper, scientists described how they used ICESat-2 data and a new model to estimate the thickness of Arctic sea ice. Comparing the new estimates to those made with the first ICESat mission (2003-2009), they found that sea ice in winter has thinned by as much as 20 percent in the past 11 years. The bottom-left map shows the February-March 2019 thickness estimate; the bottom-right map shows how much thickness has changed between 2008 and 2019. Read more about that study here.


… Measured Ice Sheet Losses Spanning 16 Years

Other research outlined the changes happening to ice on land. In a paper published April 2020 in Science, scientists chronicled 16-years of change to the Greenland and Antarctic ice sheets.

ICESat-2 data from 2019 showed that Greenland’s ice sheet had lost an average of 200 million metric tons of ice per year since the original ICESat started collecting data in 2003. Antarctica’s ice sheet lost an average of 118 million metric tons of ice per year during the same period. 

But the beauty of the new measurements from ICESat-2 is that scientists can show details of where the changes are happening. Not only can they discern where the ice sheets have been thinning or thickening, but they can see changes on the scales of individual glaciers and, for the first time, across floating ice shelves. Read this story for more details, or check out the video below.


… Detailed the Retreat of a Potentially Unstable Glacier in East Antarctica

The ice in East Antarctica is generally thought to be less vulnerable than the ice in West Antarctica and the Antarctic Peninsula. Research in 2018, however, pointed to a number of glaciers along East Antarctica’s coastline that appear to be destabilizing. A new paper published March 2020 detailed the changes happening to Denman Glacier. The stability of Denman is a concern because this one glacier in East Antarctica holds as much ice as half of West Antarctica.

Scientists used satellite radar data from the Italian COSMO‐SkyMed constellation to detect the retreat of the glacier’s grounding line—the point at which a glacier last touches the seafloor and begins to float. If the grounding line continues to retreat, warm seawater could eventually penetrate upstream and beneath the glacier, continuing to melt it from below and destabilizing it. Read the full story here


… Observed a Sixfold Increase in Ice Loss from Antarctica & Greenland Since the 1990s

Sometimes multiple satellites can tell you more than a single satellite. In research published in Nature, scientists used observations from 11 satellite missions to calculate losses from the Antarctic and Greenland ice sheets since the 1990s. They show that the ice sheets together lost 81 billion metric tons per year in the 1990s, compared with 475 billion metric tons of ice per year in the 2010s—a sixfold increase.

The meltwater associated with the ice loss boosted global sea levels by 17.8 millimeters (0.7 inches), according to a story about the research

… Calculated Ice Melt Leading to Regional Freshwater Depletion

Some losses are directly affecting the freshwater resources available to people. In the 20thcentury, the largest contributors to sea level rise came from melting ice caps and glaciers in Alaska, the Canadian Arctic Archipelago, the Southern Andes, High Mountain Asia, the Russian Arctic, Iceland, and Svalbard. 

Researchers used the GRACE and GRACE-FO satellites to determine that these seven regions lost (on average) more than 280 billion metric tons of ice per year between 2002 and 2019. The losses contributed 13 millimeters (0.5 inches) to global sea level rise. The losses also deplete a freshwater resource for communities that depend on the ice to provide meltwater for agriculture and drinking water. You can read more about the research, published April 2020 in GRL, in this story

Pathfinder for COVID-19

June 8th, 2020 by Cynthia Hall

To counter the rapid spread of COVID-19 in the winter and spring of 2020, quarantines and social distancing measures were implemented around the world. Air traffic nearly ceased; non-essential businesses were closed; and the number of vehicles on the road fell well below normal. 

Remote sensing scientists have started looking at potential changes in the environment due to these changes in human behavior. They are looking for signs of how environmental factors such as humidity, temperature, and ultraviolet radiation might play a role in the behavior of the virus. Some may also look for data related to access to water resources, which can be critical to the spread or prevention of certain diseases.

NASA’s Earth Science Data Systems program has developed a new web-based tool, the COVID-19 Data Pathfinder, which provides links to datasets that can be used to research changing environmental impacts from modified human behavior patterns, the possibility of seasonal trends in virus transmission, and water availability. The COVID-19 Data Pathfinder is also a resource for participants in NASA’s Space Apps COVID-19 Challenge, providing an intuitive means for new users to find and use NASA data.

Web view of the COVID-19 Data Pathfinder page

Explore the COVID-19 Data Pathfinder