HR: 0800h
AN: C31A-1102    [Abstracts]
TI: Monitoring of Permafrost in the Hovsgol Mountain Region, Mongolia
AU: * Sharkhuu, A
EM: anarmaash@yahoo.com
AF: Geo-Ecology Institue, Mongolian Academy of Sciences, Geo-Ecology Institute-301, Baruun Selbe-15, Ulaanbaatar, 211238 Mongolia
AU: Natsagdorj, S
EM: sharkhuu_n@yahoo.com
AF: Geo-Ecology Institue, Mongolian Academy of Sciences, Geo-Ecology Institute-301, Baruun Selbe-15, Ulaanbaatar, 211238 Mongolia
AU: Etzelmuller, B
EM: bernd.etzelmuller@geo.uio.no
AF: Department of Geosciences, University of Oslo, Department of Geosciences, Division of Physical Geography, P.O.Box 1047, Blindern, Oslo, N-0316 Norway
AU: Heggem, E S
EM: e.s.f.heggem@geografi.uio.no
AF: Department of Geosciences, University of Oslo, Department of Geosciences, Division of Physical Geography, P.O.Box 1047, Blindern, Oslo, N-0316 Norway
AU: Nelson, F E
EM: fnelson@UDel.Edu
AF: Department of Geography and Center for Climatic Research, University of Delaware, University of Delaware, Newark, DE 19716-2541 United States
AU: Shiklomanov, N
EM: shiklom@UDel.Edu
AF: Department of Geography and Center for Climatic Research, University of Delaware, University of Delaware, Newark, DE 19716-2541 United States
AU: Goulden, C
EM: cgoulden@acnatsci.org
AF: Institute of Mongolian Biodiversity and Ecological Studies, Academy of Natural Sciences, 1900 Benjamin Franklin Pkwy, Philadelphia, PA 19103 United States
AB: The Hovsgol Mountain Region is located between the coordinates of N 49°-52° and E 98°-102 ° in territory of Hovsgol Province, Mongolia. The territory is characterized by mountain permafrost, sporadic to continuous in its distribution, and occupies the southern fringe of the Siberian continuous permafrost zone. The main goal of permafrost monitoring in the region is to study recent degradation of permafrost under the influence of climate warming and human activities. Monitoring of permafrost is conducted within the framework of the Circumpolar Active Layer Monitoring (CALM) and the Global Terrestrial Network for Permafrost (GTN-P) programs. The main parameters being monitored are active layer depth and mean annual permafrost temperature at the level of the zero annual amplitude. Long-term CALM and GTN-P programs are based on ground temperature measurements in shallow to deep boreholes. Each borehole for monitoring is installed using instrumentation designed specifically to protect against air convection in them. Temperature measurements in the boreholes are made using identical thermo-resistors at corresponding depths, and carried out on the same dates each year. In addition, temperature dataloggers and thaw tubes are installed in most of the boreholes. At present, there are eight long-term (15-35 years) CALM and GTN-P active borehole sites. Boreholes are located in the Sharga valley (southwest), Burehkhan and Hovsgol phosphorite areas and Hatgal village (central part of the region) and in the Darhad depression. Initial results of the long term monitoring show that average rates of increase in active layer depth and mean annual permafrost temperature under influence of recent climate warming in the Hovsgol Mountain Region are 5-15 cm and 0.15-0.25°C per decade, respectively. The rate of permafrost degradation in bedrock is greater than in unconsolidated sediments, in ice-poor sediments more than ice-rich ones, and on north-facing slopes more than on south- facing ones. Intensive degradation of permafrost is also caused by human activities associated with land use. For example, initial results of short term (3 years) monitoring of permafrost in the northeastern shore valleys of Lake Hovsgol show that the depth of the active layer varies from 1.4 m in Borsog valley in the south to 4.8 m in Turag valley in the north, apparently in relation to livestock grazing pressure. We have also begun monitor active frost heaving on pingos in the eastern shore valleys and active thaw settlement (thermokarst) in the Darhad depression. In general, the permafrost in the Hovsgol Mountain Region is degrading more intensively than in the Khentei and Khangai Mountain Regions. The recent degradation of permafrost under the influence of climate warming and human activities leads to some changes in natural and ecological balance. In particular, our observations have indicated deforestation in the taiga zone and desertification in the steppe zone of the Hovsgol region.
DE: 0700 CRYOSPHERE (4540)
DE: 0702 Permafrost (0475)
DE: 0704 Seasonally frozen ground
DE: 0706 Active layer
DE: 0708 Thermokarst
SC: Cryosphere [C]
MN: Fall Meeting 2005