GPS资料反映的日本东北 M W 9.0地震的孕震特征
摘要
Based on the analysis of deformation characteristics in different stages of seismogenic model in oceanic plate subduction regions,we analyzed the coseismic deformation characteristics of MW9.0 earthquake using the inversion result of coseismic dislocation,whose reliability has been analyzed before used.Then,we discussed the differences between longterm and coseismic deformation from GPS data.GPS strain(rate) illustrates that the strain accumulation reflects the seduction effects of Pacific and Philippine plate before this earthquake,while the result of coseismic event reflects tension strain release whose affecting region mainly located between 35°N and 43°N.The deformation features reflected by GPS profile before earthquake and coseismic event are complementary,though the value differs by hundreds of times.GPS velocity and strain rate profile and GPS time-series results showed that the deformation had possibly reached its limit on the east coast of Japan.Through analyzing the possible precursor of this earthquake,the result including medium-and long-term forecasting,deviation to tendency background of GPS time series,pre-earthquake events and decreasing of b-value in hypocenter region,perhaps reflect the characteristics of seismogenic model in some extent.