渭河盆地及邻区场地响应和非弹性衰减研究-华南地震

文章信息/Info

Title:: Study of Inelastic Attenuation and Site Response in Weihe Basin and Its Adjacent Area

作者:: 王卫东 1; 张钰诚 1; 赵云峰 2; 郑怡 3; （1. 长安大学地质工程与测绘学院 , 西安 710054；2. 中国地震局第二监测中心 , 西安 710054； 3. 陕西省地震局 , 西安 710068）

Author(s):: WANG Weidong1; ZHANG Yucehng1; ZHAO Yunfeng 2; ZHENG Yi 3; (1.SchoolofGeologicalEngineeringandGeomatics,Chang’anUniversity,Xi’an710054,China2.SecondCrustMonitoringandApplicationCenterCEA,Xi’an710054,China3.ShanxiEarthquakeAgency,Xi’an710068,China)

摘要:: 使用 2002—2012 年渭河盆地及邻区 20 个地震的 98 条地震资料 , 采用遗传算法反演了渭河盆地及邻区的场地响应和非弹性衰减关系。研究结果表明 : 渭河盆地及邻区的非弹性衰减 Q 值随频率 f 的变化关系为 Q( f )=(623.0±127) f 0.479±0.116,1 Hz 处的 Q0 值明显大于山西、甘肃东南部等地质构造活跃区 , 与鄂尔多斯地块比较接近 , 表明其构造活动程度与鄂尔多斯地块接近 , 明显低于山西地区和甘肃东南部。6 个台站的场地响应值均在 1 附近变化 , 最大值不超过 4, 未显示明显的放大效应 , 蓝田台场地响应与其它台站相比有所差别 , 其原因有待进一步的研究。

Abstract:: Abstract: Based on 98 pieces of digital seismic data of 20 seismic events recorded at 6 seismic stations in Weihe basin and its adjacent area from 2002 ot 2012,the relation of inelastic attenuation Q value with frequency in the crust of this region and site response of the 6 stations are inversed by using genetic algorithms. The results show that the frequency-dependent Q in this region is estimated as Q( f )=(623.0±127) f 0.479±0.116 ,and the Q value at 1 Hz is 623 in this region,which is much larger than the result in the geologically active tectonic region such as Shanxi and southeastern Gansu,but is close to the Ordos block,indicating that its activity is close to that of the Ordos block,indicating that its activity is close to that of the Ordos block,but significantly lower than that of Shanxi and southeastern Gansu. The site responses of 6 stations do not show clear amplifying effect with the maximum value less than 4,which is consistent with their basement on rock. The site response in Lantian station shows some difference, and the reason should be studied further.