Satellite-based synthetic aperture
radar (SAR) can provide an additional remote-sensing tool for regional
geologic studies in arctic regions. Although SAR data do not yield direct
information on rock type and do not replace traditional optical data, SAR
data can provide useful geologic information in arctic regions where the
stratigraphic column includes a wide range of lithologies, and bedrock
exposures have been reduced to rubble by frost action. For example, in
ERS-1 SAR data from the Arctic National Wildlife Refuge (ANWR) of the northeastern
Brooks Range, Alaska, carbonate and clastic rocks can give remarkably different
radar responses on minimally reprocessed SAR data. The different radar
response of different lithologies can be attributed to variations in surface
roughness, specifically the size and angularity of scree in talus slopes.
Additional postacquisition processing can both remove many of the negative
terrain effects common in SAR data and enhance contrasts in bedrock lithology.
Because of this ability to discriminate between
gross lithologic packages, the ERS-1 SAR data can be used to provide a
regional view of ANWR and a detailed look at specific areas. A mosaic of
ERS-1 SAR data from all of ANWR provides a synoptic
1997. The American Association of Petroleum Geologists. All rights reserved.
received August 30, 1995; revised manuscript received March 11, 1996; final
acceptance August 15, 1996.
Institute, University of Alaska, Fairbanks, Alaska 99775.
SAR Facility, Geophysical Institute, University of Alaska, Fairbanks, Alaska
study was supported by sponsors of the Tectonics and Sedimentation Research
Group of the University of Alaska, Fairbanks, including ARCO Alaska, BP
(Alaska), Chevron, Exxon, Japan National Oil Co., Mobil, Phillips, and
UNOCAL. The Alaska SAR facility provided support for Richard Guritz and
reprocessing of the ERS-1 SAR data. ERS-1 SAR data were provided by the
European Space Agency under a research agreement with NASA. We would like
to thank Steve Ahlgren, Lyn McNutt, and Ken Dean for stimulating discussions
on SAR and its potential geologic applications in the Arctic, Wes Wallace
for discussions on the regional geology of northeastern Alaska and weathering
characteristics of the different stratigraphic units, and Wes Wallace,
Ken Dean, Bill Stringer, Larry Lane, M. C. Erskine, Jr., H. R. Hopkins,
and K. Biddle for helpful reviews of the manuscript.