HR: 0800h
AN: B31A-0203    [Abstracts]
TI: Severe Forest Fire Impacts to Active Layers in Alaskan Permafrost
AU: * FUKUDA, M
EM: mfukuda@pop.lowtem.hokudai.ac.jp
AB: In 2004 summer season, the Boundary Fire near Fairbanks occurred and surface organic layers severely burned in widely burnt areas. The loss of the surface organic layers may cause the deepening the active layer due to unbalancing of near surface heat budget. On-the -spot investigation was conducted in Boundary Fire area as to obtain the degree of severely of fire impacts. Thermal conductivities and depth of organic layers were measured and special index is proposed for estimation of the deepening active layer in next summer season. The ratio of thermal conductivities of residual organic layer after fire and mineral soil layers is a key of determination of the thawing effect. The results are compared with the previous fire impact which occurred in 1999 at Delta Junction in central Alaska. Other data which were obtained in eastern Siberia in 2003 were applied to verify the proposed the new index by present author.
DE: 0614 Biological effects
DE: 0634 Measurement and standards
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting