Open AccessIce flow physical processes derived from the ERS‐1 high‐resolution map of the Antarctica and Greenland ice sheets
Author(s) -
Rémy Frédérique,
Shaeffer Philippe,
Legrésy Benoît
Publication year - 1999
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1046/j.1365-246x.1999.00964.x
Subject(s) - geology , geodesy , ice stream , ice sheet , ice shelf , greenland ice sheet , geodetic datum , altimeter , sea ice , submarine pipeline , satellite , arctic ice pack , geophysics , climatology , cryosphere , geomorphology , oceanography , aerospace engineering , engineering
The ERS‐1 satellite, launched in 1991, has provided altimetric observations of the Greenland Ice Sheet and 80 per cent of the Antarctica Ice Sheet north of 82°S. It was placed in a geodetic (168‐day repeat) orbit between April 1994 and March 1995, yielding a 1.5 km across‐track spacing at latitude 70° with a higher along‐track sampling of 350 m. We have analysed the waveform altimetric data from this period to compute maps with a 1/30° grid size. Data processing consists of correcting for environmental factors and editing and retracking the waveforms. A further step consists of reducing the radial orbit error through crossover analysis and correcting the slope error to second order. The high‐resolution topography of both ice sheets reveals numerous details. A kilometre‐scale surface roughness running at 45° from the flow direction is the dominant topographic characteristic of both continents. Antarctica also exhibits many scars due to local flow anomalies. Several physical processes can be identified: abrupt transitions from deformation to sliding and vice versa, and impressive strike‐slip phenomena, inducing en echelon folds.