Find the Earthquake Fault by SAR Interferogram
A lot of small deformations can be detected anywhere in SAR interferogram and most of their locations correspond to the locations where existing faults appear above the ground.
Not displacement itself but the horizontal gradient of displacement shows the location of a fault slip to detect small deformation.
Left figure is a conceptual diagram showing the gradient of a ground deformation and the position of a fault. The fault exits in the area with the large gradient.
Estimation of the location of the surface fault caused
by the South Hyogo Prefecture Earthquake, 1995
Figure showing the gradient of the surface deformation
Figure showing the location of the surface fault estimated from the gradient of the surface deformation (in Kobe)
Figure showing the location of the surface fault estimated from the gradient of the surface deformation (in Awaji)
Estimation of the location of the surface fault caused
by the Mid North Iwate Prefecture Earthquake, 1998
Figure showing the location of the surface fault estimated from the gradient of the surface deformation
Cross-section of the surface deformation and the landscape
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Two left figures show the result of the gradient analysis based on the 2.5 dimensional processing of the deformation.
As well as the surface deformation caused by the South Hyogo Prefecture Earthquake, this analysis reveals a variety of surface faults and the correlation between the topography and the surface deformation.