HR: 1340h
AN: GP33B-1257 [Abstracts]
TI: Magnetotelluric Surveys Using Near and Very far Remote References
AU: * Lee, S
EM: seongkon@kigam.re.kr
AF: KIGAM (Korea Institute of Geoscience and Mineral Resources), Gwahang-no 92, Yuseong-
gu, Daejeon, 305-350, Korea, Republic of
AU: Lee, T
EM: megi@kigam.re.kr
AF: KIGAM (Korea Institute of Geoscience and Mineral Resources), Gwahang-no 92, Yuseong-
gu, Daejeon, 305-350, Korea, Republic of
AU: Song, Y
EM: song@kigam.re.kr
AF: KIGAM (Korea Institute of Geoscience and Mineral Resources), Gwahang-no 92, Yuseong-
gu, Daejeon, 305-350, Korea, Republic of
AU: Cull, J
EM: jim.cull@sci.monash.edu.au
AF: Monash University,
Wellington Rd, Clayton, VIC 3800, Australia
AB:
Magnetotelluric (MT) soundings have been made on two traverse lines to the
north and west of the Century Zinc mine in NW Queensland, Australia, in
order to image the intermediate to deep structure in the region. The purpose
of the MT surveys lies in delineating the extension of the Termite Range
Fault (TRF), a major structure on the Lawn Hill Platform running through the
Century Zinc mine with north-west strike direction.
During the survey, we operated the remote reference (RR) site in Gregory
Downs, which is roughly 80 km apart from the field site. High quality MT
signals have been obtained using remote reference techniques. Besides the RR
site in Australia, a permanent monitoring site in Esashi, Japan, which is
approximately 4600km away, had been operating during the whole period of the
survey simultaneously. MT data were acquired in the field location
simultaneously together with remote data at remote stations with the help of
GPS time synchronization.
Long period pulsations observed in this survey generally showed dominant
Hx polarization than Hy. We also observed high coherency between MT
signal at the very-far remote reference site and local site for two
frequency ranges; around 1 Hz and 10-2 Hz, especially in Hx
component. We tried to extract MT impedances using RR in Japan and compared
the results from two RR's. The results shows that apparent resistivities and
phases processed with two remote reference magnetic data are compatible.
DE: 0600 ELECTROMAGNETICS
DE: 0900 EXPLORATION GEOPHYSICS
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting