COSEISMIC RESPONSE OF PET GRAVIMETER AT LHASA SEISMIC STATION

In this paper, the coseismic response of PET gravimeter at Lhasa seismic station is studied from 4 aspects of surface wave delay time, first motion direction, wave amplitude, lasting time of coseismic response. The results indicate that:(1) there is a significant positive correlation between the surface wave delay time of the coseismic response and epicentral distance;(2) first motion direction has no distribution law;(3) the amplitude of coseismic response is not only related to magnitude of earthquake but also to the epicentral distance of the earthquake.(4) the coseismic wave of distant earthquake are mostly pulse form while the coseismic wave of local earthquake also show step besides pulse;(5) there is no significant proportion relation between the lasting time of the coseismic response and magnitude.