拉萨地震台PET重力仪同震响应特征

从面波延迟时间、初动方向、波幅、同震持续时间等4个方面研究拉萨台PET重力仪的同震响应特征,结果表明：（1）同震响应的面波延迟时间与地震震中距离具有较好正相关性；（2）初动方向没有规律；（3）同震响应的波幅不仅与地震震级大小有关,还与震中距远近有关；（4）远震的同震波一般表现为脉冲形式,近震除了脉冲外,还有阶跃；（5）同震波的延续时间与震级没有明确的比例关系.这有助于对重力仪器进行深入的了解,可以为未来西藏地区监测台网布设方案提供参考数据.

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 re- sponse. 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 pro- portion relation between the lasting time of the coseismic response and magnitude.