Earth ID: 3403

Antarctic Plumbing: Lake Englehardt's Subglacial Hydraulic System

Visualizations by Alex Kekesi Released on February 19, 2007

ICESat satellite laser altimeter elevation profiles from 2003-2006 collected over West Antarctica reveal numerous regions of temporally varying elevation. MODIS satellite imagery over roughly the same time period collaborates where these subglacial fluctuations have occurred. These observations have led scientists to conclude that subglacial water movement is happening in this lake region, revealing a widespread, dynamic subglacial water system that could provide important insights into ice flow and the mass balance of Antarctica's ice.

This animation begins by showing the Antarctic continent through the eyes of the Aqua/AMSR-E sensor. As the camera approaches the Lake area we transition to the MODIS Mosaic Of Antarctica (MOA) revealing a December 2002 3-day average of MODIS data over Lake Englehardt. This then does a quick transition to a December 2005 3-day MODIS average. Next, an orange swathe of ICESat data passes over the lake and ICESat elevation data taken on October 24, 2003 is extruded from the surface eventually hovering above the December 2002 3-day MODIS average. The orange ICESat slice then morphs into ICESat elevation data taken on June 2, 2006 for this same region. As the ICESat elevation data dips, the underlying MODIS data transforms again into the December 2005 3-day average revealing the corresponding lake depression.

ICESat elevation data taken on October 24, 2003 is shown in orange. The underlying gray 'shadow' corresponds to where the elevation data lies on the surface. The underlying MODIS data is a 3 day average taken in the month of December 2002.

ICESat elevation data taken on June 2, 2006 is shown in orange. The underlying gray 'shadow' corresponds to where the elevation data lies on the surface. The underlying MODIS data is a 3 day average taken in the month of December 2005.

For More Information

http://www.nasa.gov/vision/earth/lookingatearth/antarctic_plumbing.html

Visualization Credits

Alex Kekesi (Global Science and Technology, Inc.): Lead Animator
Cindy Starr (Global Science and Technology, Inc.): Visualizer
Lori Perkins (NASA/GSFC): Animator
Ted Scambos (NSIDC): Scientist
Bob Bindschadler (NASA/GSFC): Scientist
Helen Amanda Fricker (Scripps Institution of Oceanography, University of California, San Diego): Scientist
Laurie Padman (Earth and Space Research): Scientist

Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio The Blue Marble Next Generation data is courtesy of Reto Stockli (NASA/GSFC) and NASA's Earth Observatory.

Science Paper:
'An Active Subglacial Water System in West Antarctica Mapped from Space', Science Express, 2007 Feb 15

Short URL to share this page:
https://svs.gsfc.nasa.gov/3403

Missions:
Ice, Cloud, and land Elevation Satellite (ICESat)
Terra

Data Used:

Terra and Aqua/MODIS/MODIS Mosaic of Antarctica (MOA) Image Map also referred to as: MOA

Mosaic - National Snow and Ice Data Center (NSIDC) and the University of New Hampshire - 2003/11/30 - 2004/02/29

Staff from the National Snow and Ice Data Center (NSIDC) and the University of New Hampshire have assembled two digital image maps of surface morphology and optical snow grain size that cover the Antarctic continent and its surrounding islands. The MODIS Mosaic of Antarctica (MOA) image maps are derived from composites of 260 MODIS (Moderate-resolution Imaging Spectroradiometer) orbit swaths acquired between 20 November 2003 and 29 February 2004. The MOA provides a cloud-free view of the ice sheet, ice shelves, and land surfaces, and a quantitative measure of optical snow grain size for snow- or ice-covered areas. All land areas larger than a few hundred meters that are south of 60° S are included in the mosaic, as well as persistent fast ice regions and some grounded icebergs present near the coast in the 2003-2004 austral summer. The MOA surface morphology image map is derived from digitally processed MODIS Band 1 data. The optical snow grain size image is compiled using a normalized ratio of atmospherically corrected, calibrated band radiance data from Bands 1 and 2.

http://nsidc.org/data/nsidc-0280.html

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