Earth  ID: 4097

Greenland's Mega-Canyon beneath the Ice Sheet

Subglacial topography plays an important role in modulating the distribution and flow of meltwater beneath the ice known as basal water flow. This animation portrays topographic data of the bedrock under the Greenland ice sheet derived from ice-penetrating radar data. Clearly evident in the topography is a 750-km-long subglacial canyon in northern Greenland that is likely to have influenced basal water flow from the ice sheet interior to the margin. The authors suggest that the mega-canyon predates ice sheet inception and has influenced basal hydrology in Greenland over past glacial cycles. (See reference under "Science Paper" below)

Starting with a view of the surface of Greenland, the animation zooms closer to the surface as the ice sheet is stripped away to reveal the false-color topography of the bedrock that lies beneath. Regions above sea level are shown in shades of green while areas below zero are colored by shades of brown. Yellow indicates the area near sea level. The topography is exaggerated from 12 to 40 times in order to accentuate the topographic relief. Visible in the topography from about the midpoint of Greenland to its Northwest coast is the 750-km-long subglacial canyon described by the authors.



Visualization Credits

Cindy Starr (GST): Lead Visualizer
Greg Shirah (NASA/GSFC): Animator
Jefferson Beck (USRA): Producer
J. L. Bamber (School of Geographical Sciences, University of Bristol, UK): Scientist
Michael Studinger (NASA/GSFC): Scientist
Laurence Schuler (ADNET): Project Support
Ian Jones (ADNET): Project Support
Please give credit for this item to:
NASA's Goddard Space Flight Center Scientific Visualization Studio
The Blue Marble Next Generation data is courtesy of Reto Stockli (NASA/GSFC).

Science Paper:

Bamber, J.L., Siegert, M.J., Griggs, J.A., Marshall, S., Spada, G. Paleofluvial canyon drains subglacial water from northern Greenland, Science, 2013.

Bamber, J. L., Griggs, J. A., Hurkmans, R. T. W. L., Dowdeswell, J. A., Gogineni, S. P., Howat, I., Mouginot, J., Paden, J., Palmer, S., Rignot, E., and Steinhage, D.: A new bed elevation dataset for Greenland, The Cryosphere, 7, 499-510, 10.5194/tc-7-499-2013, 2013. (Available here.)

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Operation IceBridge

Data Used:

Greenland bed elevation dataset by Bamber, et al., 2013
Data Compilation - Bristol Glaciology Centre, University of Bristol - 1970 - 2012
Greenland Mapping Project (GIMP) Digital Elevation Model also referred to as: GIMP Greenland DEM
Data Compilation - Courtesy of Ian Howat, OSU - 2003 - 2009
Terra and Aqua/MODIS/Blue Marble: Next Generation also referred to as: BMNG
The Blue Marble data is courtesy of Reto Stockli (NASA/GSFC).
Note: While we identify the data sets used in these visualizations, we do not store any further details nor the data sets themselves on our site.

NASA Science >> Earth
GCMD >> Earth Science >> Land Surface >> Topography >> Topographical Relief
GCMD >> Earth Science >> Land Surface >> Topography >> Topographic Effects
GCMD >> Earth Science >> Hydrosphere >> Glaciers/Ice Sheets >> Ice Sheets
GCMD >> Earth Science >> Cryosphere >> Glaciers/Ice Sheets >> Ice Sheets
GCMD >> Earth Science >> Land Surface >> Topography
DLESE >> Physical geography

GCMD keywords can be found on the Internet with the following citation: Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version