The complete (3‐D) surface displacement field in the epicentral area of the 1999 M_W7.1 Hector Mine Earthquake, California, from space geodetic observations

Abstract

Abstract.We use Interferometric Synthetic Aperture Radar (InSAR) data to derive continuous maps for three orthogonal components of the co-seismic surface displacement field due to the 1999 M•o 7.1 Hector Mine earthquake in southern California. Vertical and horizontal displacements are both predominantly antisymmetric with respect to the fault plane, consistent with predictions of linear elastic models of deformation for a strike-slip fault. Some deviations from symmetry apparent in the surface displacement data may result from complexity in the fault geometry.

Three-dimensional deformation caused by the Bam, Iran, earthquake and the origin of shallow slip deficit

“…We combine the four projections of surface deformation (Figures 1a-d) to deduce the full 3-D vector displacement filed due to the Bam earthquake 4,8 . Figures 1e and 1f show the vertical and horizontal components of the coseismic deformation, respectively.…”

“…Over the last decade, new information about the near-field deformation due to several large shallow earthquakes was obtained with the help of the space-borne Synthetic Aperture Radar (SAR) measurements [1][2][3] . Interpretations of the spatially continuous SAR data from the best documented seismic events including the M w 7.3 Landers 4 , the M w 7.6 Izmit 5,6 , and the M w 7.1 Hector Mine 3,7,8 earthquakes all reveal the maximum seismic moment release in the middle of the seismogenic layer (the average depth of 4-6 km). While a gradual decay in the coseismic slip at the bottom of the seismogenic layer is likely compensated by postseismic and interseismic strain accumulation, and is reasonably well understood 9-11 , the apparent discrepancy between slip in the middle and shallow parts of the seismogenic layer remains enigmatic.…”

“…Table 1 lists the radar acquisitions used in this study. We generated four independent projections of the coseismic displacement field using differences in the radar phase 17 and the radar amplitude 8,18 before and after the earthquake from both the ascending and descending orbits (see Methods section). The …”

The Use of C-/X-Band Time-Gapped SAR Data and Geotechnical Models for the Study of Shanghai’s Ocean-Reclaimed Lands through the SBAS-DInSAR Technique

“…The latter assumption is reasonable, as the soil consolidation stages, as well as the mechanisms induced by the weight of the buildings, which have been built in the new city, are, at most, responsible for vertical movements of the terrain. Nevertheless, the lack of sufficiently large archives of time-overlapped ascending/descending SAR images over Lingang New City (with respect to the reclaimed areas) makes the measurement of the east-west deformation rates directly from SAR data unreliable, as shown, for instance, by using the methods in [55,[70][71][72][73][74][75]. Moreover, such a strategy can be extended to other cases where deformation components in east-west directions cannot be considered negligible.…”

“…Moreover, such a strategy can be extended to other cases where deformation components in east-west directions cannot be considered negligible. This can be done by effectively combining the strategies adopted here, and the combination methods discussed in [55,[70][71][72][73][74][75], which exploit SAR data acquired by multiple sensors and different orbital positions (e.g., from ascending and descending passages). In addition, the adopted combination scheme can be further generalized to the point where more than two time-gapped sequences of SAR images are available.…”