The Global Land Ice Measurements from Space GLIMS project

*Department of Geography, University of Zurich *For the GLIMS consortium.

Figure 85.1 Tasman glacier, New Zealand. Depicted terrain section is about 25 X 25 km. The ASTER satellite image was taken on 29 April 2000. North is to the top. Imaging is within the project Global Land Ice Measurements from Space (GLIMS) project. (Satellite data courtesy of NASA/GSFC/ METI/ERSDAC/JAROS, and US/Japan ASTER science team; processed by A. Kaab, University of Zurich.) The ASTER satellite sensor carries cameras with different viewing angles. Based on such imagery, the three-dimensional form of the Earth's surface can be computed. The resulting digital terrain models can be used for various analyses to understand glaciers and their environment. The image shows the ASTER satellite image draped over a three-dimensional model of the Earth surface. Mount Cook, the highest peak of New Zealand, is to the middle left of the depicted terrain section. (See www. blackwellpublishing.com/knight for colour version.)

VNIR sensor can be pointed cross-track by up to ±24°, which allows for repeat imaging as frequently as every second day in response to urgent priorities.

The ASTER sensor also proved to be very suitable for assessing glacier hazards and managing related disasters. This became particularly evident during the Kolka-Karmadon disaster (Fig. 85.2; Kaab et al., 2003). During the late evening of 20 September 2002, a combined rock and ice avalanche of several million cubic metres started from the Dzimarai-khokh peak in the Kazbek massif, Russian Caucasus (lower left of the images). The large avalanche fell onto the Kolka glacier tongue. The impact of the initial rock and ice avalanche sheared off a major part of the Kolka glacier tongue and started a sled-like rock and ice avalanche of tens of million cubic metres. The Kolka rock and ice avalanche crossed the tongue of the Maili glacier. On its devastating journey northward, the avalanche picked up a large amount of loose sediments in the valley bottom. A few minutes after initiation and 18km down-valley from the Kolka glacier, the gigantic mass overran the lower parts of the village of Karmadon, killing dozens of inhabitants. Shortly beyond this point, the avalanche was abruptly stopped by the narrowing valley flanks of the Karmadon gorge, and roughly 100 million cubic metres of ice and debris were deposited (middle

Figure 85.2 Kolka-Karmadon rock and ice avalanche, Caucasus, 20 September 2002. Infra-red false colour composites of satellite imagery of 22 July 2001 (before) and 27 September 2002 (after the event) were taken from the ASTER sensor aboard the NASA TERRA spacecraft. North is to the top. Image size is about. 15 X 15 km. Imaging is within the Global Land Ice Measurements from Space (GLIMS) project. (Images courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and US/Japan ASTER science team; processed by A. Kaab, University of Zurich.) See text for description of the event. (See www.blackwellpublishing.com/knight for colour version.)

Figure 85.2 Kolka-Karmadon rock and ice avalanche, Caucasus, 20 September 2002. Infra-red false colour composites of satellite imagery of 22 July 2001 (before) and 27 September 2002 (after the event) were taken from the ASTER sensor aboard the NASA TERRA spacecraft. North is to the top. Image size is about. 15 X 15 km. Imaging is within the Global Land Ice Measurements from Space (GLIMS) project. (Images courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and US/Japan ASTER science team; processed by A. Kaab, University of Zurich.) See text for description of the event. (See www.blackwellpublishing.com/knight for colour version.)

top of the images). Large amounts of mud were suddenly pressed out of the mass. The resulting mudflow, up to 300 m wide, ravaged the valley bottom below Karmadon, travelling for another 15 km northward from the gorge. In total, the avalanche and subsequent mudflow killed over 120 people. The avalanche deposits at Karmadon soon started to block the rivers entering the gorge. Over a period of approximately 1 month the dammed river water progressively flooded the populated areas near Karmadon that had not been directly affected by the avalanche. The ASTER imagery provided invaluable help in understanding and documenting the event, and in supporting the disaster management.

The GLIMS project closely collaborates with the World Glacier Monitoring Service (WGMS) and the international working group on glacier and permafrost hazards in mountains under the International Commission on Snow and Ice (ICSI) and the International Permafrost Association (IPA).

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