Publication Date:
2006
Description:
We use interferometric synthetic aperture radar, Global Positioning System,
and teleseismic data to constrain the relative location of coseismic slip from 11
earthquakes on the subduction interface in northern Chile (23-25 S) between the years
1993 and 2000. We invert body wave waveforms and geodetic data both jointly and
separately for the four largest earthquakes during this time period (1993 Mw 6.8; 1995
Mw 8.1; 1996 Mw 6.7; 1998 Mw 7.1). While the location of slip in the teleseismic-only,
geodetic-only, and joint slip inversions is similar for the small earthquakes, there are
differences for the 1995 Mw 8.1 event, probably related to nonuniqueness of models that
fit the teleseismic data. There is a consistent mislocation of the Harvard centroid
moment tensor locations of many of the 6 〈 Mw 〈 8 earthquakes by 30-50
km toward the trench. For all models, the teleseismic data are better able to resolve
fine details of the earthquake slip distribution. The 1995 earthquake did not rupture to
the maximum depth of the seismogenic zone (as defined by the other earthquakes). In
addition to the above events, we use only teleseismic data to determine the rupture
characteristics of four other Mw 〉 6 earthquakes, as well as three Mw 〉
7 events from the 1980s. All of these earthquakes appear to rupture different portions
of the fault interface and do not rerupture a limited number of asperities.
Keywords:
Source
;
Crustal deformation (cf. Earthquake precursor: deformation or strain)
;
InSAR
;
7215
;
Seismology:
;
Earthquake
;
source
;
observations
;
7240
;
Subduction
;
zones
;
6924
;
Radio
;
Science:
;
Interferometry
;
1240
;
Geodesy
;
and
;
Gravity:
;
Satellite
;
geodesy:
;
results
;
1242
;
Seismic
;
cycle
;
related
;
deformations
