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Kolka Glacier, Russia

IMAGE: Mount Kazbek, Aug. 13, 2002
Aug. 13, 2002. Larger image (345 Kb)


IMAGE: Mount Kazbek, Oct. 17, 2002
Oct. 17, 2002. Larger image (389 Kb)


IMAGE: Mount Kazbek
Oct. 19, 2002. Larger image (1 Mb)
IMAGE: Ice mass
A mass of ice and debris buried the village of Karmadon and filled the surrounding basin after it slid from the Kolka Glacier. Lakes are forming on the edges of the ice mass as it melts. There is a threat of their sudden outburst, which would affect villages further down the Genaldon River valley. (This photograph was taken by Sergei Chernomorets on Oct. 6, 2002.) Larger image (274 Kb)

The crew of the International Space Station observed and documented the result of the catastrophic glacier collapse and landslide that occurred on the northern slope of Mount Kazbek, which is one of the highest mountains in the Caucasus range. This image centers on the peak of Mount Kazbek, and clearly shows the surrounding glaciers and peaks. On Sept. 20, 2002, the collapse of a hanging glacier from the slope of Mount Dzhimarai-Khokh onto the Kolka Glacier triggered an avalanche of ice and debris that went over the Maili glacier terminus then slid more than 24 kilometers (15 miles). It buried small villages in the Russian Republic of North Ossetia, killing dozens of people. Where the ice stopped, the glacial debris flow dammed rivers further below. Several lakes formed and one of them flooded a village. There lakes are now threatening to burst and form debris flows.

The Kazbek-Dzhimarai Glacier group is over 70 square kilometers (27 square miles) in area. Glacier collapses have occurred in the past -- first accounts date back to the 18th century. Exactly a hundred years ago, in 1902, the same kind of catastrophe happened in this valley, killing 32 people. Later studies suggested that the 1902 avalanche was the result of a glacier surge. In 1969, the Kolka Glacier surged again, but there were no casualties and the villages were not affected. The 1969 surge was studied by a special expedition but research in the area stopped after the glacier stabilized. The latest data on the September 2002 catastrophe raise doubts about the cause of the 1902 collapse -- it is possible that the 1902 event resulted from a similar cascade of collapses.

IMAGE: Panorama
This panoramic photo shows Maili Glacier (left) and the Kolka Glacier terminus (center and right), including the area where huge ice masses of Kolka Glacier slipped (center) and moved over the Maili Glacier terminus (left). A new lake (right) formed on the surface of the remaining mass of the Kolka Glacier after the collapse. (The photograph was taken by Dr. Dmitry Petrakov on Oct. 5, 2002.) Larger image (271 Kb)

The Expedition Five crew on the International Space Station -- Dr.Peggy Whitson, Valery Korzun and Sergei Treschev -- have been photographing this area for the Russian URAGAN project, which is studying changes in the world's glaciers in response to global climate change. On Aug. 13, 2002, roughly one month before the glacier collapse, the station crew photographed the mountain. Although scientists have predicted the possibility of large glacial collapses as the climate warms, at the time of the first image, no one predicted that tragedy would strike the mountain village of Karmadon a little more than a month later.

The STS-112 crew aboard Space Shuttle Atlantis photographed the glacier Oct. 17, 2002, and a new station image was taken on Oct. 19 and downlinked about a week later. This most recent station image is very timely for a number of reasons. First, scientists are combining the astronaut photographs with Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, data to observe the rapid changes in a meltwater lakes that has been formed by the collapse. An ASTER image taken Sept. 27, showed no lake near the Kolka Glacier terminus.

IMAGE: Genaldon River valley
The Genaldon River valley is situated above the buried villages. The bottom of the valley is now covered by ice. (This photograph was taken by Olga Tutubalina on Sept. 22, 2001.) Larger image (16 Kb)

The Russian team first sighted a lake during its field trip on Oct. 5, and detected it in the ASTER image dated Oct. 6. The lake surface area has increased between Oct. 6 and the most recent astronaut photograph on Oct. 19. The lake is potentially dangerous, because it can produce disastrous outburst mudflows. The succession of images shows changes in the glacier surface and of the periglacial area during the last few weeks. A second reason the most recent photograph from the space station is important is its unique oblique look angle. This view allows visualization of the three-dimensionality of the ridges and provides enough detail to allow scientists to estimate the volume of the initial glacier collapse. No satellites presently in orbit can provide this combination of spatial detail and oblique look angle. With oblique look angles and shadows, mountains appear in dramatic relief, and this technique has been used to photograph such areas as Mount Everest and Dhaulagiri.

IMAGE: Maili Glacier terminus
The white area in the center right is the Maili Glacier terminus, which has been buried by the ice from the Kolka Glacier. (This photograph was taken by Olga Tutubalina on Sept. 22, 2001.) Larger image (36 Kb)

International Space Station crewmembers are surveying glaciers around the world using their low orbit and high-magnification lenses to get high spatial resolution. Images such as these highlight the advantages of human observations. The crew's ability to look obliquely to better capture the three-dimensionality of the landscape and take advantage of different Sun angles on the landscape provides imagery that is both visually spectacular and easy to interpret. Crewmembers can also select lenses and frame the specific region of interest.

IMAGE: Kolka Glacier
This is a partial view of the Kolka Glacier (center). (The photograph taken by Sergei Chernomorets on Sept. 22, 2001.) Larger image (19 Kb)

The group of Russian investigators includes Moscow State University scientists Dr. Dmitry Petrakov, Dr. Victor Popovnin, Dr. Olga Tutubalina and Sergei Chernomorets of the University Center for Geodynamics and Monitoring and Dr. Lev Dessinov of the Russian Academy of Sciences. In September 2001, the team visited the Kolka Glacier to assess its state. After the collapse they conducted analysis of satellite images taken by the atsronauts and provided by NASA's Johnson Space Center, and then organized a field trip to correct NASA's analysis and gather additional information. They plan to continue monitoring in this area using satellite images.

Moscow State University's work is supported by the Russian Foundation for Basic Research.

Astronaut photographs ISS005-E-09691, STS112-E-6002 and ISS005-E-09691 were provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

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