利用同一地点的2个地震在相同台站记录的P波到时差是一个常数这一原理,找到了与汶川主震位置相近的余震,并利用台站距震中近,且记录波形清晰、完整的优势,对余震进行了定位,依此确定了汶川主震的位置和发震时刻。结果是震中位于31°1.26'N、103°22.50'E;震源深度7.9km;发震时刻(北京时间)为2008年5月12日14时27分58.80秒。

Under the principle that the arrival time difference of P wave of the 2 earthquakes with the same locations recorded by the same station is a constant，the paper found the aftershocks near the Wenchuan earthquake，and with the advantage of close distance to the epicenter with clear and complete recorded waveforms，determined the epicenter and origin time of the quake: the position of 31. 049°N，103. 338°E，the depth of 6. 0km，and origin time ( Beijing time) of May 12，2008，14: 27: 58. 79．

河北省地震局重点项目“临时地震台网的建设与管理”资助