Calculation of Ice Velocities in the Jakobshavn Isbrae Area Using Airborne Laser Altimetry

• Published in: Remote sensing of environment Vol. 67; no. 2; pp. 194 - 204
• Main Authors: Abdalati, W, Krabill, W.B
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-02-1999; Elsevier Science
• Subjects: Applied geophysics; Earth sciences; Earth, ocean, space; Exact sciences and technology; External geophysics; Flow patterns; Glaciers; Internal geophysics; Laser applications; Snow. Ice. Glaciers; Velocity measurement; Arctic region; Greenland; Greenland ice sheet; glaciers; laser methods; Space remote sensing; surveys; accuracy; remote sensing; ice; velocity; drainage basins; synthetic aperture radar; airborne methods; interpretation; polar regions; filtering; landform evolution; altimetry; standard deviation
• ISSN: 0034-4257; 1879-0704
• DOI: 10.1016/S0034-4257(98)00086-8

The ability to measure velocities of fast-moving glaciers is essential to the understanding and interpretation of their dynamics and related processes. This is especially important in the Jakobshavn drainage basin of the Greenland ice sheet, where a significant portion of the ice sheet mass loss occurs and the iceberg calving rate is high. In this article, we present a method for using airborne laser altimetry data to determine surface velocities in portions of the Jakobshavn drainage basin that have distinct elevation features. By examining correlations between repeat elevation surveys, the motion of these features, the most distinct of which are crevasses, is tracked. Results show that for areas with a standard deviation in elevation in excess of 1 m, displacement of features can be tracked to a precision of 1–2 m, and the corresponding velocities can be retrieved. The maximum velocity of the Jakobshavn Isbrae, at its calving front, is found to be nearly 7 km yr
−1. Ice stream boundaries and flow patterns can also be observed in the derived velocity data.