Two Scientists Have a Frank and Honest Discussion about Antarctica

The Reference Elevation Model of Antarctica (REMA) provides the first, high resolution (8-meter) terrain map of nearly the entire continent. REMA is constructed from hundreds of thousands of individual stereoscopic Digital Elevation Models (DEM) extracted from pairs of submeter (0.32 to 0.5 m) resolution DigitalGlobe satellite imagery, including data from WorldView-1, WorldView-2, and WorldView-3, and a small number from GeoEye-1, acquired between 2009 and 2017, with most collected in 2015 and 2016, over the austral summer seasons (mostly December to March).Each individual DEM was vertically registered to satellite altimetry measurements from Cryosat-2 and ICESat, resulting in absolute uncertainties of less than 1 m over most of its area, and relative uncertainties of decimeters.This visualization compares the spatial resolution of REMA with DEM data from RADARSAT. This visualization explores the spatial resolution of the REMA data. The camera starts out at a global view of Antarctica before zooming into the Ross Archipelago region. RADARSAT DEM data is shown as the camera pushes in, showing the limits of the data resolution. A wipe transition reveals the REMA data, exposing additional details as the camera moves down towards the surface. Terrain is represented as a mesh to show the full resolution of the data. The camera flies up a valley, exploring the detailed REMA data. LIMA imagery is revealed at the end of the visualization. Coming soon to our YouTube channel. High resolution still image of the Ross Archipelago region High resolution still image of RADARSAT DEM High resolution still image of REMA High resolution still image of REMA High resolution still image of REMA High resolution still image of REMA (elevation) with LIMA (imagery) 360 (spherical) version of the visualizationComing soon to our YouTube channel. Related pages

This visualization shows the ocean currents circulating around the Pine Island Bay and flowing under the Pine Island Glacier. This image shows the ocean currents circulating in the Pine Island Bay. This image shows the ocean currents circulating in the water beneath the Pine Island Glacier. Glaciers surrounding the Amundsen Sea in Antarctica have been rapidly melting. As glaciers flow out from land to the ocean, large expanses of ice behind their leading edges float on the seawater. The point on a glacier where it first loses contact with land is called the grounding line. Nearly all glacier melt occurs on the underside of the glacier beyond the grounding line, on the section floating on seawater as the warmer ocean currents erode the base of the floating ice.This visualization shows the ocean currents in the Amundsen Sea derived from the "Estimating the Circulation and Climate of the Ocean" (ECCO) ocean circulation model. The visualization approaches the Pine Island Glacier, dives beneath the water and views the ocean flows circulating beneath the floating ice. The surface of the ice sheet is exaggerated by 4x while the topography below sea level is exaggerated by 15x for the purpose of clarity. Related pages

This visualization depicts changes in Antarctic land ice thickness as measured by the ICESat (2003-2009) and ICESat-2 (2018-) satellites. The camera zooms into a region near the Kamb ice stream to compare ICESat and ICESat-2 beam tracks. The beam intersections are highlighted to explain how the data at these points are used to measure how land ice has changed over time. After exploring a few regions in detail, the camera moves out to a global view and an ocean temperature dataset is revealed. This visualization depicts changes in Greenland land ice thickness as measured by the ICESat (2003-2009) and ICESat-2 (2018-) satellites. The camera zooms into a region near the Zachariae Isstrom glacier to compare ICESat and ICESat-2 beam tracks. The beam intersections are highlighted to explain how the data at these points are used to measure how land ice has changed over time. This high resolution still image depicts changes in Antarctic land ice thickness as measured by the ICESat (2003-2009) and ICESat-2 (2018-) satellites. This high resolution still image depicts changes in Greenland land ice thickness as measured by the ICESat (2003-2009) and ICESat-2 (2018-) satellites. The future response of the Antarctic Ice Sheet to changes in climate is the single largest source of uncertainty in projections of sea level rise. If the ice sheet melted completely it would raise sea levels by 57 meters, a process that would unfold over millennia. One key to understanding how the ice sheet will respond in the future is to observe and analyze how the ice sheet has reacted to changes in climate over the past decades, where satellites observations are available. One key to understanding ice sheet change is to examine records of elevation change that show where the ice sheet is thinning and thickening due to changing environment. Recent analysis of incredibly precise surface elevations collected by NASA’s ICESat and ICESat-2 satellite laser altimeters reveals complex patters of ice sheet and ice shelf (floating extensions of the ice sheets) change that are the combined consequence of changes in melting by the ocean, changes in precipitation and, changes at the bed of the glacier where the ice sheet slides across the underlying bedrock. The researchers do this my finding locations where tracks of measured elevation intersect, measuring the change in elevation and correct for changes in the average density of the surface using models. Coherent regional patters of elevation change reveal the underlying mechanism responsible causing ice sheet change. One of the most striking features in the data is the Kamb Ice Stream that once flowed rapidly into the Ross Ice Shelf but that stopped flowing due to an increase friction (resistance to flow) likely caused by changes in the availability of liquid water at its base. Strong patters of thinning are visible all along the Amundsen Cost where ice shelves are rapidly thinning in response to increased melting by warm ocean waters. Melting of ice shelves do not directly contribute to changes in sea level, since they are already floating, but they do indirectly impact how fast the grounded ice is able to flow into the ocean. Ice shelves are located at the fronts of the glaciers and help to regulate how fast the ice flows into the ocean. As the ice shelves thin they become less able to hold back the inland ice, causing the grounded glaciers to accelerate and thin. In the East, broad patters of thickening reveal that the East Antarctic Ice Sheet is growing most likely in response to increases in precipitation relative to some unknown time in the past. The thickening is strongest along the coast of Dronning Maud Land where enhanced moisture transport has resulted in increased snowfall. Despite the diversity of gains and losses, losses in the West (208 cubic kilometers of water per year or Gt) greatly outpace Gains (90 Gt per year) in the east resulting in a total Antarctic mass change loss of 118 Gt per year. As the Greenland Ice Sheet responds to warming oceans and atmosphere it has become one of the largest contributors to sea level rise and will continue to be for the foreseeable future. Scientists are working to determine more precisely how much more ice will be lost and when that loss will occur. One key approach to doing this is to analyze changes in the ice sheets elevation over the past decades where satellite observations are available. By finding the intersection of elevation track measurements collected by NASA’s ICESat (2003-2009) and ICESat-2 (2018-) satellite laser altimeters, researchers are able to make very precise measurements of elevation change that can be converted to estimates of mass change after correcting for changes snow density using models. The combination of long time-span between measurements and the high accuracy of NASA’s satellite laser altimeters allows the researchers to make highly detailed maps of mass change that provide insights into the mechanism behind the ice sheets rapid rate of loss. Thinning can be seen around the periphery of the ice sheet where elevations are closest to sea level and rates of surface melting are highest. This pattern is punctuated by localized areas of extreme thinning where large glaciers come into contact with warm ocean waters. Unlike the uniform pattern of low-elevation thinning that is being driven by increased melting due to warmer summer air temperatures, these concentrated areas of thinning occur where outlet glacier have sped up. These glaciers have sped up in response to some combination of retreating ice front position, changes in the slipperiness at the bed of the glacier due to changes in liquid water at the ice-rock interface and due to change in the rate frontal melting due to an increase in the heat content of the ocean waters that come into contact with the glacier front. Juxtaposed on the pattern of rapid thinning along the periphery of the ice sheet is a broad pattern of thickening in the high-elevation interior of the ice sheet. This pattern of thickening suggests that increases in snowfall, relative to sometime in the past, are partly compensating for increased losses due to enhanced melt and accelerated glacier flow. Overall low-elevation losses greatly outpace high-elevation gains resulting in 3200 cubic kilometers of water (Gt) being lost from the ice sheets and entering the oceans, raising global mean sea level by 8.9 mm. Related pages

Space Down to Earth (1970) Creator(s): National Aeronautics and Space Administration. 10/1/1958- (Most Recent)Series: Headquarters' Films Relating to Aeronautics, 1962 - 1981Record Group 255: Records of the National Aeronautics and Space Administration, 1903 - 2006Production Date: 1970Scope & Content: This film shows the role of applications satellites in solving Earthbound problems. The film illustrates what such satellites were doing in 1970, and what can be expected in the next decade, the 1970s, in such fields as performing Earth resources surveys, tracing and measuring pollution levels, locating mineral resources, making long-range weather forecasts, providing more precise Earth measurements, and improving navigation and communications. Related pages

For complete transcript, click here. The 3D flythough of the rift in the Pine Island Glacier on Oct. 26, 2011, created entirely through photogrammetric processing.of Digital Mapping System imagery taken from NASA's DC-8 aircraft during an Operation IceBridge field campaign. NASA's DC-8 flew over the Pine Island Glacier Ice Shelf on Oct. 14, 2011, as part of Operation IceBridge. A large, long-running crack was plainly visible across the ice shelf. The DC-8 took off on Oct. 26, 2011, to collect more data on the ice shelf and the crack. The area beyond the crack that could calve in the coming months covers about 310 square miles (800 sq. km). For More InformationSee [http://earthobservatory.nasa.gov/IOTD/view.php?id=77266](http://earthobservatory.nasa.gov/IOTD/view.php?id=77266) Related pages

A new map changes our understanding of how ice flows across Antarctica. Slow, interior flows have been sped up to make them more visible. The colors represent the real flow velocity magnitude.This video is also available on our YouTube channel. With all flows shown at the proper scale, only the fastest ice movement is visible. With colors representing velocity magnitude removed, glacier direction stands out against the icy background. Black lines mark continental ridges that separate regions of ice moving toward different parts of the coastline. Harsh snows have blanketed Antarctica for so long that the continent has built up an ice sheet a mile thick from bedrock to surface in most places. Despite the ice cap's grip on the rocky landmass below, friction can only hold back the ice so much. A new, first-of-its-kind map from NASA reveals icy Antarctica as a landscape of constant movement. NASA scientists at the Jet Propulsion Laboratory and UC Irvine have charted this movement for the first time, using Canadian, Japanese and European satellite data to create a record of the speed and direction of ice flow across the entire continent. The map reveals glaciers and tributaries in patterned flows stretching hundreds of miles inland, like a system of rivers and creeks. Slow-moving flows found in largely unexplored East Antarctica defied previous understanding of ice migration. And scientists discovered a ridge that splits Antarctica from east to west. Explore the visualizations below to see the new benchmark map scientists can use to study the extent and speed of changes to the largest ice sheet in the world. For More InformationSee [NASA.gov](http://www.nasa.gov/topics/earth/features/antarctica20110818.html) Related pages

Return to P.I.G.: The Long Wait for Science Return to PIG provides an update to PIG Ice Shelf: First Contact. Though NASA researcher Bob Bindschadler had hoped to return to Pine Island Glacier Ice Shelf and continue his research during the 2009 season, this video explians how plans hit a snag. Sometimes science takes time, especially when it comes to dealing with the forbidding conditions of Antarctica. Related pages

Portion of longer video flying over Antarctica, using data from the Landsat Image Mosaic of Antarctica (LIMA). Selected as one of the "Top Ten Stories of Landsat's 40 Years," LIMA is the first ever, high-resolution, true color map of the Antarctic continent. This guided tour of the area surrounding McMurdo Station in Antarctica uses the Landsat Image Mosaic of Antarctica (LIMA). It's a great way to experience the frozen continent without any risk of frostbite.This is a narrated version of entry #3482: Landsat Image Mosaic of Antarctica Flyover of McMurdo Station and Dry Valleys.For complete transcript, click here.This video is also available on our YouTube channel. Version of the guided tour of the area surrounding McMurdo Station in Antarctica using the Landsat Image Mosaic of Antarctica (LIMA) created for the National Science Foundation Visualization Competition. In 2007, more than 1,100 Landsat 7 images were used to create the first ever, high-resolution, true color map of Antarctica. The Landsat Image Mosaic of Antarctica (LIMA) is a virtually cloud-free, 3-D view of Antarctica's frozen landscape produced by NASA, working with the National Science Foundation, the U.S. Geological Survey and the British Antarctic Survey.Visualizers stitched together Landsat 7 satellite imagery acquired in 1999 and 2001 with a digital elevation model and field data measurements. For More InformationSee [http://lima.nasa.gov](http://lima.nasa.gov) Related pages

As you can see from this short video, the logistics of setting foot on the Pine Island Glacier ice shelf turned out to be a real challenge and the first trip had both its ups and its downs. Nonetheless, Bindschadler welcomes the challenge and has high hopes for what his continued research on Pine Island might uncover. For a complete transcript of this video, please click here This past January NASA scientist Robert Bindschadler led an expedition to a previously untouched part of Antarctica that may be one of the best places to gauge how global warming is affecting the continent. Pine Island Glacier Ice Shelf (PIG for short) is believed to be among the most vulnerable spots ot melting on Earth, but it's also among the most remote. While satellite observations provide a wide-angle view of the action on the glacier, boots on the ground with high tech drills and sensors are needed to provide the close up shots to fill in the blanks. Antarctica footage provided by Polar-Palooza/Passport to Knowledge For More InformationSee [http://pigiceshelf.gsfc.nasa.gov](http://pigiceshelf.gsfc.nasa.gov) Related pages

Animation zooms down to the area where iceberg B-15A split in two between 10-7-03 and 10-9-03. McMurdo Station can be seen on the final frame of this animation. McMurdo Station is towards the top of the image, and appears as a white dot with 4 lines (runways-roads) branching off it. Video slate image reads "Iceberg B-15A: RADARSAT Match-frame rendered RADARSAT approach to the B-15A iceberg area. McMurdo Station can be seen towards the very top of the final image as a white dot with 4 lines (runways/roads) branching off of it". Match-frame rendered RADARSAT approach to the B-15A iceberg area. Useful as a frame-of-reference for the location of the B-15A iceberg. Match-framed to animations 2838, 2840, and 2841 for post-production. Related pages