HR: 0830h
AN: C31B-0395    [PDF]
TI: Helicopter electromagnetic and glaciers: example from Mt. Adams, Washington.
AU: * Deszcz-Pan, M
EM: maryla@usgs.gov
AF: USGS, Denver Federal Center, MS 964, Denver, CO 80225 United States
AU: Finn, C A
EM: cfinn@usgs.gov
AF: USGS, Denver Federal Center, MS 964, Denver, CO 80225 United States
AU: Anderson, E D
AF: USGS, Denver Federal Center, MS 964, Denver, CO 80225 United States
AB: Helicopter Electromagnetic (HEM) surveys over Mt. Adams and Mt. Baker were conducted in May of 2002. The objective of the surveys was to delineate the areas of alterations under glacial cover in order to estimate the hazards associated with the weaker, clay zones. The altered, water saturated zones are electrically very conductive in comparison with unaltered rocks and glaciers (ice). Finding altered zones under glaciers with current HEM methods is relatively straightforward. In this paper we examine a more difficult task of measuring ice thickness with HEM techniques. We are evaluating the conditions that data have to satisfy in order to distinguish between electrically resistive unaltered rocks and glaciers. An example of inversion results from the HEM survey over Mt. Adams is provided.
DE: 0600 ELECTROMAGNETICS
DE: 0900 EXPLORATION GEOPHYSICS
DE: 0910 Data processing
DE: 0925 Magnetic and electrical methods
DE: 1863 Snow and ice (1827)
SC: Cryosphere [C]
MN: 2003 Fall Meeting