新疆皮山M_S6.5地震远场长周期地面运动分析

FAR-SOURCE LONG-PERIOD GROUND MOTIONS ANALYSIS OF XINJIANG PISHAN EARTHQUAKE WITH M_S6.5

皮山M_S6.5地震获取的39组强震记录中,有6组都不同程度的记录到后续面波现象,处于塔里木盆地边缘的罕南力克台和亚曼亚台尤为清晰,这种面波产生原因是台站位于盆地边缘,并且台基下土层结构较为复杂。以罕南力克台和亚曼亚台为例,伽师台做为对比,进行时域、频域、能量函数、场地条件等分析。这种面波以瑞利波成分为主,周期为1.3 s。两个台站记录到的面波和剪切波携带的能量近似,为总地震波能量的22%左右。虽然所选的3个强震台站都处于塔里木盆地边缘地带,但由于伽师台下土层结构简单,并没有表现出后续面波现象。

In the 39 group of strong motion records of Xinjiang Pishan MS 6.5 earthquake, 6 groups of them showed subsequent surface wave in different degrees. Hannanlike station and Yamanya station recorded subsequent surface wave particularly clear due to their location of Tarim basin edge and complicated soil structure under station base. Taking Hannanlike station and Yamanya station as examples, analyzed their time-domain, frequency-domain, energy, sites comparing with those conditions of Jashi station. It was found that surface wave, mainly rayleigh wave, period was 1.3 s. And through energy function values, we obtained that surface wave and shear wave boosted approximate energy values, which was about 22% of total seismic wave energy. Jashi station didn＇ t show subsequent surface wave phenomenon because of its simple soil structure, although these 3 selected stations were all located at edge of Tarim Basin.