The Research on Method for Investigating Inland Crustal Deformation with GPS Data

Sagiya, Takeshi*

I examined new methodologies for investigating inland seismogenic faults with GPS data. Inland crustal deformation is sometimes significantly affected by plate coupling at subduction zones. Therefore it is quite important to remove such effects from original GPS data in order to discuss inland seismogenic faults. It is suggests that we need a simultaneous analysis of nationwide GPS data and introduction of physical constraint such that the coupling vectors are directed along the relative plate motion. On the other hand, I compared geologically estimated slip rates of active faults and geodetic data around those faults in order to chech consistency between these two data sets. Although these two data have significantly different strain rates, it is concluded that direct comparison of these two data sets is not reasonable and other aspects such as the displacement rate can be comprehensively understood. In addition, crustal deformation associated with active faults appears within a finite width, which is highly variable among active faults, around each active fault. Though these investigations, an applicability of GPS data for investigating inland seismogenic faults is confirmed.