InSAR Measurements of Surface Deformation in the Epicentral Region of the Nenana Mountain and Denali Fault Earthquakes of Oct.23 & Nov. 3, 2002
Authors: Ford, A.L.J., Bruhn, R.L. and Forster, R.R.
Conference: American Geophysical Union Annual meeting
Dates: 6-10 December 2002
Abstract:We are using InSAR to investigate regional surface deformation surrounding the epicenters of the Oct. 27 (M=6.7) and Nov. 3 (M=7.9), 2002 earthquakes on the Denali fault in the Alaska Range. Our goal is to study relationships between fault structure and earthquake processes in this transpressional fault system.
The earthquake epicenters are located near a large bend in the trace of the Denali fault that is located at 1470 W. The component of surface displacement in the radar range-direction is found over an area of about ~2x104 km2 by interferometric analysis of repeat-pass, C-band synthetic aperture radar data (InSAR). We have successfully constructed an interferogram that shows the cumulative displacement field caused by the M=6.7 and M=7.9 earthquakes. The interferometric fringes on the north side of the Denali fault trend from east-northeast to northwest creating a broad fan-like pattern of displacement contours that are broadly consistent with dilatational deformation at the end of a transpressional right-lateral fault dislocation.
Deformation is more localized along the south side of the Denali fault where the fringes trend westnorthwest and the displacement gradient is significantly greater than on the north side of the fault, possibly caused by vertical displacement associated with a mapped thrust fault. Overall, fringe patterns appear to reflect a mixture of right-lateral and thrust faulting that is consistent with seismological and geological observations of earthquake deformation.
http://www.agu.org/meetings/fm02/fm02-pdf/fm02_S72F.pdf
Source: Manual
Preferred by: Andrew Ford