Mark Fahnestock, a scientist with the Geological Institute of the University of Alaska Fairbanks, has assembled annual mosaics of all the glaciers in Alaska and the Yukon using Landsat images going back to 1972. Using these mosaics, Mark is able to study glacier motion and speed.All music published by Atmosphere Music Ltd [PRS]: Inducing Waves, composer Ben Niblett [PRS] Jon Cotton [PRS]; Critical Pathway, composer Rik Carter [PRS]; Emerging Discovery, composer Rik Carter [PRS]Complete transcript available.Watch this video on the NASA Goddard YouTube channel. || 13492_Alaska_Glaciers_mosaic_print.jpg (1920x1080) [1.0 MB] || 13492_Alaska_Glaciers_mosaic_print_searchweb.png (320x180) [135.5 KB] || 13492_Alaska_Glaciers_mosaic_print_thm.png (80x40) [9.0 KB] || 13492_Alaska_Glaciers.mov (1920x1080) [4.3 GB] || 13492_Alaska_Glaciers.mp4 (1920x1080) [516.6 MB] || 13492_Alaska_Glaciers.webm (1920x1080) [38.7 MB] || 13492_Alaska_Glaciers-captions.en_US.srt [5.9 KB] || 13492_Alaska_Glaciers-captions.en_US.vtt [5.9 KB] ||

Some call it the eighth wonder of world; others say it's the next Great Wall of China. Upon completion in 2009, the Three Gorges Dam will be the world's largest hydroelectric power generator. One of the few man-made structures so enormous that it's actually visible to the naked eye from space, NASA's Landsat satellite has had a closer look, providing detailed, vivid views of the dam since its inception in 1994. The dam is built along the Yangtze River, the third largest in the world, stretching more than 3,900 miles across China before reaching its mouth near Shanghai. Historically, the river has been prone to massive flooding, overflowing its banks about once every ten years. During the 20th century alone, Chinese authorities estimate that some 300,000 people were killed from Yangtze River floods. The dam is designed to greatly improve flood control on the river and protect the 15 million people and 3.7 million acres of farmland in the lower Yangtze flood plains. Observations from the NASA-built Landsat satellites provide an overview of the dam's construction. The earliest data set, from 1987, shows the region prior to start of construction. By 2000, construction along each riverbank was underway, but sediment-filled water still flowed through a narrow channel near the river's south bank. The 2004 data shows development of the main wall and the partial filling of the reservoir, including numerous side canyons. By mid-2006, construction of the main wall was completed and a reservoir more than 2 miles (3 kilometers) across had filled just upstream of the dam. To read more about the Three Gorges Dam, please click here. This animation was designed in three parts: Part 1: The first part of this animation zooms in to the Three Gorges Dam and travels backward and forward through time emphasizing the dam construction and filling of the reservoir. This animation then continues seemlessly into Part 2. Part 2: Starting where Part 1 leaves off, the camera flies up the 2006 data showing the high water levels that have already filled the multiple gorges upstream. Part 3: Identical to Part 2, except showing the 1987 data prior to the dam construction. ||

This visualization shows a sequence of Landsat-based data in the Pacific Northwest. There is one data set for each year representing an aggregate of the approximate peak of the growing season (around August). The data was created using a sophisticated algorithm called LandTrendr. LandTrendr analyzes 'stacks' of Landsat scenes, looking for statistical trends in the data and filtering out noise. The algorithm evaluated data from more than 1,800 Landsat Thematic Mapper images, nearly 1 Terabyte of raw imagery, to define the life histories of each of more than 336 million pixels on the landscape. The resulting trends identify periods of stability and change that are displayed as colors.In these false color images, the colors represent types of land; for example, blue areas are forests; orange/yellow areas are agriculture; and, purple areas are urban. Each 'stack' is representative of a Landsat scene. There are 22 stacks stitched together to cover most of the U.S. Pacific Northwest. This processed data is used for science, natural resource management, and education.We move in to the southwest corner of the data set near Redwood National Park and proceed on a slow tour through a portion of the data set. Time loops from 1984 through 2011 as we move. We move over to Mount Shasta, then up the Cascade Range, passing Crater Lake National Park, the Three Sisters, Mount Jefferson, Mount Hood, Mount Saint Helens, Mount Adams, Mount Rainier, Mount Baker, and the North Cascades National Park. Next we move west over Seattle and pass over Olympic National Park, then we head back south down the Willamette Valley back to Redwood National Park.Don't miss this related narrated visualization ||

This visualization shows a sequence of Landsat-based data in the Pacific Northwest. There is one data set for each year representing an aggregate of the approximate peak of the growing season (around August). The data was created using a sophisticated algorithm called LandTrendr. LandTrendr analyzes 'stacks' of Landsat scenes, looking for statistical trends in the data and filtering out noise. The algorithm evaluated data from more than 1,800 Landsat Thematic Mapper images, nearly 1 Terabyte of raw imagery, to define the life histories of each of more than 336 million pixels on the landscape. The resulting trends identify periods of stability and change that are displayed as colors.In these false color images, the colors represent types of land; for example, blue areas are forests; orange/yellow areas are agriculture; and, purple areas are urban. Each 'stack' is representative of a Landsat scene. There are 22 stacks stitched together to cover most of the U.S. Pacific Northwest. This processed data is used for science, natural resource management, and education.The visualization zooms into the Portland area showing different types of land such as agricultural, urban, and forests. We move south to a region that was evergreen forest for a number of years (blue), then was clear cut in 1999 (orange), then began to regrow (yellow). A graph shows the trajectories for a particular location in the clearcut as the years repeat. The dots represent the original data from Landsat; and, the line represents LandTrendr analysis. We move over to the Three Sisters region to show an area of pine forest that becomes infested with bark beetles in 2004. Next, we move to the southern foothills of Mount Hood where a budworm infestation is in progress; around 1991, the worms move on to another area and shrubs start to regrow. Next wemove to the east side of Mount Rainier National Park to see another budworm outbreak followed by shrub regrowth. Finally, we move to the west of Mount Rainier where we can see widespread clear cutting outside of the park, but no clear cutting inside the protected park land.Don't miss this related tour of the region. ||

Timelapse animation of Lake Mead and the city of Las Vegas, Nevada, from 1972-2021, as captured by Landsat sensors. The images are false-color, showing healthy vegetation in red. || Las_Vegas-wide-2021_print.jpg (1024x576) [226.8 KB] || Las_Vegas-wide-2021_searchweb.png (320x180) [119.1 KB] || Las_Vegas-wide-2021_thm.png (80x40) [7.7 KB] || Las_Vegas_1972-2021-tw.mp4 (1920x1080) [64.7 MB] || Las_Vegas-wide-2021.tif (1920x1080) [7.9 MB] || Las_Vegas_1972-2021-tw.webm (1920x1080) [8.0 MB] || Las_Vegas_1972-2021-yt.mp4 (1920x1080) [129.5 MB] || Las_Vegas_1972-2021.mov (1920x1080) [2.3 GB] ||

A water-rich polka dot pattern takes over the traditional rectangular patchwork of fields in this 40 year sequence of Landsat images showing the dry Texas panhandle near the town of Dalhart. In this series, vegetation appears red and the bare soil of fallow fields or sparsely vegetated grasslands appear white to green. The blue-gray X near the center of the images marks the town of Dalhart. ||

Poplar Island is being rebuilt by the U.S. Army Corps of Engineers using dredged mud from the Baltimore Harbor which lies about 30 miles (about 48 kilometers) north of the island. Reconstruction of the island began in 1998 with the erection of dikes to contain the mud.The growing island is a wildlife sanctuary, a hatchery for hundreds of diamondback terrapins and home to about 170 different species of birds including terns and bald eagles. NASA and the U.S. Department of the Interior through the U.S. Geological Survey (USGS) jointly manage Landsat. The USGS preserves the archive of Landsat images and distributes all of the 40-years of Landsat data free over the Internet. ||

A combination of lightning, drought and human activity caused fires to scorch more than one-third of Yellowstone National Park in the summer of 1988. Within a year, burn scars cast a sharp outline on the 793,880 acres affected by fire, distinguishing wide sections of recovering forest, meadows, grasslands and wetlands from unburned areas of the park. After more than two decades, satellite instruments can still detect these scars from space.In the time-lapse video below, a series of false-color images collected by USGS-NASA Landsat satellites from 1987 to 2018 show the burning and gradual regeneration of Yellowstone's forests following the 1988 fire season. Watch as burn scars (dark red) quickly replace large expanses of healthy green vegetation (dark green) by 1989. Notice how the scars slowly fade over time as new vegetation begins to grow and heal the landscape.Landsat Project Scientist Jeff Masek has been studying the recovery of the forest after the 1988 Yellowstone fires. In the video below, he talks about how Landsat satellites detect the burn scars from space and distinguish them from healthy, un-burned forest and from new growth. ||

Forest fires and logging are the two main drivers of change in this area within Trinity National Forest in northern California. Roger Eckart and his siblings bought a grandfathered-in piece of private land within the forest in 1972, and so together the Eckart family and the Landsat program have observed changes in the forest for over 40 years. ||

Saudi Arabia is drilling for a resource possibly more precious than oil.Over the last 24 years, it has tapped hidden reserves of water to grow wheat and other crops in the Syrian Desert. This time series of data shows images acquired by three different Landsat satellites operated by NASA and the U.S. Geological Survey.The green fields that dot the desert draw on water that in part was trapped during the last Ice Age. In addition to rainwater that fell over several hundred thousand years, this fossil water filled aquifers that are now buried deep under the desert's shifting sands.Saudi Arabia reaches these underground rivers and lakes by drilling through the desert floor, directly irrigating the fields with a circular sprinkler system. This technique is called center-pivot irrigation.Because rainfall in this area is now only a few centimeters (about one inch) each year, water here is a non-renewable resource. Although no one knows how much water is beneath the desert, hydrologists estimate it will only be economical to pump water for about 50 years.In this series of four Landsat images, the agricultural fields are about one kilometer (.62 miles) across. The images were created using reflected light from the short wave-infrared, near-infrared, and green portions of the electromagnetic spectrum (bands 7, 4, and 2 from Landsat 4 and 5 TM and Landsat 7 ETM+ sensors). Using this combination of wavelengths, healthy vegetation appears bright green while dry vegetation appears orange. Barren soil is a dark pink, and urban areas, like the town of Tubarjal at the top of each image, have a purple hue.Landsat 4 launched in 1982 and provided scientific data for 11 years until 1993. NASA launched Landsat 5 in 1984 and it ran a record-breaking 28 years, sending back what was likely its last data in 2011. Landsat 7 is still up and running; it was launched in 1999. The data from these and other Landsat satellites has been instrumental in increasing our understanding of forest health, storm damage, agricultural trends, urban growth, and many other ongoing changes to our land.NASA and the U.S. Department of the Interior through the U.S. Geological Survey (USGS) jointly manage Landsat, and the USGS preserves a 40-year archive of Landsat images that is freely available data over the Internet. Download a still image showing four of the years: 1987, 1991, 2000, and 2012. ||