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Earth Matters

A Second Look at Susquehanna Sediment

December 6th, 2019 by Adam Voiland
A MODIS image of the mid-Atlantic on November 6, 2019. Credit: NASA Earth Observatory

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.

Mark Trice in his Maryland DNR office. The body of water on the map behind his left shoulder is Chesapeake Bay and the Atlantic Ocean. Image courtesy of Mark Trice.

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.

Chart credit: U.S. Geological Survey

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.

Building Roads in the Congo Rainforest

November 27th, 2019 by Kasha Patel
A former private logging road in the Northern Republic of Congo is now being converted to a public road. Photo credit: Fritz Kleinschroth

In a recent article, we described a study of how road networks in the Congo Basin have changed over the past 15 years and how they have affected deforestation rates. Those networks have grown significantly, but not all roads lead to long-term forest destruction. By closing roads when they are no longer needed, people can help avoid permanent damage to the forest.

Though the researchers conducted much of their research via remote sensing and computer work, they also made several trips into the Congo Basin. Their photos shed more light on some of the economic activities in the rainforest.

Riparian forest in the Republic of Congo. Photo credit: Nadine Laporte

The Congo Basin is covered by tropical rainforests and swamps and is famous for its rich biodiversity. At two million square kilometers (1.2 million square miles), the Congo rainforest is the second largest in the world and about the size of Mexico. The image above shows a forested area near a stream in the Republic of Congo.

As road networks have expanded, the roads are bringing people deeper into the jungle and closer to wildlife. In general, forest roads lead to more human activity and to unregulated or destructive events, such as poaching, mining, or illegal logging. The image below demonstrates how roads are encroaching on wildlife habitats.

Gorilla by a roadside in Republic of Congo. Photo credit: Fritz Kleinschroth

The majority of new roads are built for selective logging activities, which is one of the main economic activities in the rainforest. Companies practice selective logging where only the most valuable tree species are cut, which usually results in cutting one tree per hectare on average. In order to harvest this timber though, the companies must build roads, usually unpaved, that allow the trucks and tractors to drive deep into the forest. The photos below show scenes of timber extraction and a timber yard.

Timber extraction in Republic of Congo. Photo credit: Fritz Kleinschroth

Timber yard of a logging company in Cameroon. Photo credit: Fritz Kleinschroth

Sometimes roads are used by farmers to reach further into the forest and establish small-scale agricultural plots. The image below shows a small landholder in a forest near Mbandaka in the Democratic Republic of Congo. The woman is carrying a basket of manioc (cassava). She is also holding a maranthaceae leaf, which is commonly used for wrapping and cooking on a fire.

Photo credit: Scott Goetz

In the recent study, the researchers found that deforestation rates were highest around older, open roads. Specifically, the highest rates were found in the Democratic Republic of Congo due to agriculture and a high population density.

Researchers showed deforestation rates were the lowest around abandoned or closed roads. Abandoned roads reduce human traffic and allow vegetation to grow over the dirt path. The image below shows an abandoned road in the Republic of Congo that is overgrown with regenerating trees and plants. These plant species pictured are popular for gorillas to feed on and can help restore the gorillas’ natural habitat.

Photo credit: Fritz Kleinschroth

Abandoned roads were most commonly found inside logging concession areas. After a logging company was no longer using the road, the road was often closed or abandoned. Sometimes the road can be closed off by simply using a log to prevent vehicles from entering, as shown below.

To read the accompanying article, click here: When a Road Leads to Deforestation

Photo credit: Fritz Kleinschroth

November Puzzler

November 26th, 2019 by Kasha Patel

Every month on Earth Matters, we offer a puzzling satellite image. The November 2019 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.

November 2019 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 in the image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t 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 A Burial Site Fit for an Emperor Image of the Day for the answer.

NASA Data Helps Assess Landslide Risk in Rohingya Refugee Camps

November 20th, 2019 by Lia Poteet, NASA Earth Science Division Applied Sciences Program

Camp managers and other officials overseeing Rohingya refugee camps in Bangladesh are now incorporating NASA satellite observations into their decision-making. Information like daily rain totals can help inform how to lay out refugee camps and how to store supplies. The goal is to reduce the risk to refugees from landslides and other natural hazards.

NASA and Columbia University scientists and staff survey efforts to halt additional land loss at a Rohingya refugee camp in Bangladesh.  Credit: UN Development Programme/Eno Jonathan

Since August 2017, more than 740,000 Rohingya refugees have fled from Myanmar (Burma) to Bangladesh. Many of them have sought shelter in camps in the hilly countryside, where landslide risks are greatest. When refugee camps were built in the southeastern part of the country, many plants and trees were removed — taking with them the roots that could hold the soil in place and help stabilize the landscape when heavy rains come.

Increasing this danger is Bangladesh’s intense monsoon season. Approximately 80 percent of the country’s yearly rain falls from June to October, bringing with it an increased risk of flash flooding and landslides. For instance, July 2019 storms dropped 14 inches of rain in just 72 hours, causing 26 landslides in Rohingya refugee camps around Cox’s Bazar, Bangladesh. One person was killed and more than 4,500 others were left without shelter.

“We have little information on landslides,” said Hafizol Islam, who is in charge of one of the most densely populated camps at Cox’s Bazar. “It is unpredictable for us and can happen at any time.”

Now Islam and other camp managers have access to maps and a website (updated daily) that provides near real-time NASA data on land use, rainfall, and elevation. Data come from the Global Precipitation Measurement (GPM) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites, among other sources. Taken together, these maps and data provide a clearer picture of when and where landslide hazards are concentrated.

“With landslides, flash floods, and rapid development, the terrain of these camps is constantly changing,” said Robert Emberson, a postdoctoral fellow at NASA’s Goddard Space Flight Center.

Tarps help prevent rainfall from infiltrating the soil and destabilizing the hillside.
Credit: UN Development Programme/Eno Jonathan

Emberson and other researchers from NASA’s Earth Applied Sciences Disasters Program and Columbia University’s International Research Institute for Climate and Society (IRI) are using new approaches to work alongside humanitarian end-users and develop products to address pressing needs in vulnerable settings. The partnership seeks the feedback of the local people affected and develops maps based on their input.

“We need to understand if, why, and when existing risk information is being used,” said Andrew Kruczkiewicz of IRI, one of the principal investigators of the project. “This strengthens the development of data services for humanitarian emergencies, where decisions and priorities change rapidly. Working in teams that bridge traditional professional and disciplinary boundaries gives data and climate scientists the opportunity to learn more about decision-making in specialized contexts.” 

The need for coordination is pressing. Bangladesh has seen steadily increasing rainfall totals over the past 50 years. Climate change is making monsoons in Asia more extreme, and it may be doubling the likelihood of extreme rainfall events even before monsoon season begins.

The partnership with NASA and IRI helps the UN agencies to assess risks like landslides or flash flooding and supports the disaster management in a scientific way to save lives and reduce damages in the refugee camps,” said Cathrine Haarsaker, a project manager for UNDP Disaster Risk Management.

Refugee camps built in the Bangladeshi hillside are vulnerable to sudden landslides.
Credit: UN Development Programme/Eno Jonathan

Emberson said seeing the camps in person brought home the importance of connecting with the people on the ground. “Working with satellite data can sometimes feel quite abstract and separate from the people within the images,” he said. “Visiting the camps not only helped us understand more about the specific problems associated with landsliding to help improve our models in the future, but also drove home the human side to this disaster, emphasizing the urgency of our work.”

Read the full story here…

October Puzzler

October 8th, 2019 by Adam Voiland


Every month on Earth Matters, we offer a puzzling satellite image. The October 2019 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 in the image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t 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 Virginia’s Volcanic Past Image of the Day for the answer.

NASA GLOBE Fall Data Challenge: What’s Up in Your Sky?

October 4th, 2019 by Joe Atkinson, NASA Langley Research Center

Who knew that being a scientist could be as easy as pointing your phone at the sky? This month, NASA and the GLOBE Program are asking citizen scientists to take out their phones and report what kinds of clouds they see above them.

From October 15 to November 15 citizen scientists young, old, and in-between can submit up to ten cloud observations per day using the GLOBE Observer app or one of GLOBE’s other data entry options (for trained members). Participants with the most observations will receive a personalized thank you from a NASA scientist.

“What excites researchers about GLOBE observations is the ability to see what’s up in the sky from volunteers’ perspectives all over the world,” said Marilé Colón Robles, lead for the GLOBE Clouds Team at NASA’s Langley Research Center. “What our eyes can see is difficult to fully duplicate with instruments. Merging these views is what makes a complete and impactful story.”

“We want to do a data challenge in the fall and see if there are any differences from what was observed during the spring data challenge of 2018,” said Colón Robles. “From thin, high clouds that are hard for satellites to detect to dust storms that impact our daily lives, these observations play an important role in better understanding our atmosphere.”

At NASA, scientists work with a suite of satellite instruments known as the Clouds and the Earth’s Radiant Energy System (CERES). Though they have these highly sensitive instruments, it can sometimes be difficult for scientists to distinguish features such as cirrus clouds from snow cover in their imagery because both are cold and bright from a satellite perspective. By comparing satellite images from a particular area with data submitted by citizen scientists, researchers can differentiate between the two.

Lucky GLOBE observers might make an observation while the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) is overhead. CALIPSO is a joint mission between NASA and the French space agency (CNES) that uses laser pulses to measure clouds and atmospheric aerosols. Citizen scientists who make observations at the same time and place as CALIPSO will receive an emailed satellite comparison of CALIPSO’s measurements showing features such as high clouds, dust, and smoke. Scientists are especially interested in these observations in order to improve their understanding of dust storms. During the challenge, make sure you turn on daily satellite notifications in the app or use this satellite overpass website to see the schedule for your location.

“Last year’s challenge gave researchers special glimpses into cloud types around the world,” said Colón Robles. “Photographs provided by observers gave insight into events such as dust storms and wildfires. Our hope is to once again learn from the community and together study our atmosphere.”

The 2018 data challenge, which took place in the spring, received more than 56,000 cloud observations from more than 15,000 locations in 99 countries and Antarctica.

NASA is a sponsor of GLOBE, an international science and education program that provides students and the public with the opportunity to participate in data collection and the scientific process. NASA GLOBE Observer is a free smartphone app that lets anyone make citizen science observations from the palm of their hand.

Cloud Identification Resources and Tips

Data collection and data entry help

August Puzzler

August 19th, 2019 by Adam Voiland

Every month on Earth Matters, we offer a puzzling satellite image. The August 2019 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 in the image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t 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 Canadian Canola Fields Image of the Day for the answer. Congratulations to Rebecca Evermon for being the first reader to recognize that the image showed canola fields.

July 2019 Puzzler

July 23rd, 2019 by Kathryn Hansen


Every month on Earth Matters, we offer a puzzling satellite image. This month we are skipping the natural-color satellite image and showing something out of the ordinary. But we assure you: it came from a NASA satellite. 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 in the image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t 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!

Some of our Favorite Apollo and Moon Images

July 19th, 2019 by Kathryn Hansen

Even after 50 years, the day of Apollo 11 Moon landing remains a vivid memory in many minds. But even generations that were not born before July 20, 1969, can appreciate the monumental achievement through numerous historical accounts, video, and photographs. 

Inspection of EO’s 20-year archive turned up numerous occasions on which we have celebrated the Apollo program and the Moon—Earth’s only natural satellite. Below we highlight a few of our favorites. Still hungry for more Earth and Moon imagery? Check out our gallery “Earth From Afar.”

Apollo 11 Launch Pad

On July 16, 1969, Apollo 11 lifted off from launch pad 39A at Cape Canaveral, a headland along Florida’s Atlantic coast. Neil Armstrong, “Buzz” Aldrin, and Michael Collins began their journey to the Moon. On June 9, 2002, the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 satellite captured this true-color image of launch pad 39A and neighboring pad 39B. 

By launching from the east coast of Florida, NASA took advantage of both geography and physics. Rockets could aim eastward and fly over the Atlantic Ocean, far away from heavily populated areas should anything go wrong. And within the continental United States, Florida is closest to the Equator. Launching from a locality close to the Equator enables the rocket to harness Earth’s orbital energy to boost its own trajectory. Read more.

Looking Back from Apollo 11



These two photographs were taken by the crew on their outbound journey from Earth to the Moon. Apollo 11 launched from Cape Canaveral at 9:32 a.m. on July 16, 1969, and these photos were captured that day. The top view shows the full disk of Earth, with bits of California, the Pacific Northwest coast, and Alaska peeking through the cloud cover in a scene otherwise dominated by the Pacific Ocean. The second, closer view shows more of the western United States and Canada, with the Rocky Mountains filling much of the center of the scene and the Arctic ice cap at the top. Read more.

Apollo 11 Landing Site

The Lunar Reconnaissance Orbiter launched on June 18, 2009, and began sending back images of the Moon on June 23. Launched to map the surface of the Moon, LRO was still moving towards its near-surface orbit when it acquired this image of the Apollo 11 landing site. When the orbiter reaches its final orbit, it will image the Moon’s surface at a resolution of 0.5 meters, providing an image that is about two times more detailed than the one shown here. Read more.

A Different Perspective on the Harvest Moon

This image from Apollo 11 shows the Earth rising over the limb of the Moon much as the Harvest Moon does from our planetary perspective. Over the stark, scarred surface of the Moon, the Earth floats in the void of space, a watery jewel swathed in ribbons of clouds.
 
While the Harvest Moon has allowed humans throughout history to coax “just a little more” from the Earth’s bounty before the onset of winter, images of our home from the Moon helped raise awareness of the Earth as a rare (and perhaps unique) planetary ecosystem. The Apollo 11 images provided a global backdrop for the building U.S. environmental movement, including a surge of citizen-led environmental cleanups in the 1960s and 70s, and implementation of key national environmental policies. Read more.

MISR Where on Earth…? Quiz #31

July 12th, 2019 by MISR Outreach Team

The Multi-angle Imaging SpectroRadiometer (MISR) team at NASA is pleased to offer its 31st “Where on Earth?” quiz.

To participate, visit https://climate.nasa.gov/quizzes/misr_quiz_31/

When you visit that page and press “start,” you will be presented with nine multiple-choice questions (one for each of MISR’s nine cameras) about the image above. You may research the answers using any website or reference material you like. You cannot go back to previous questions, so make sure of your answer before proceeding!

The natural color image above was acquired by MISR’s vertical-viewing camera in July 2017 and represents an area about 300 kilometers by 240 kilometers (190 miles by 150 miles). Note that north is not necessarily at the top of the image.

If you answer all of the questions correctly, you will be eligible for a prize. The deadline for entries is July 18, 2019, at 4:00 p.m. Pacific Time. Note – if you try to answer on this blog, you will not be eligible for the prize, so click here to take the quiz.