The updated crustal attenuation in North China using ML amplitude tomography
Shunping Pei1, Yongshun John Chen2
1 Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2 Computational Geodynamics Laboratory, Department of Geophysics, School of Earth and Space Sciences, Peking University, Beijing 100871, China
The updated crustal attenuation in North China using ML amplitude tomography
Shunping Pei1, Yongshun John Chen2
1 Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2 Computational Geodynamics Laboratory, Department of Geophysics, School of Earth and Space Sciences, Peking University, Beijing 100871, China
摘要We have updated the lateral variations of the quality factor Q0 (Q at 1 Hz) beneath the crust of North China using ML amplitude tomography with near three times data. The data were selected from the Annual Bulletin of Chinese Earthquakes (ABCE) in 1985-2009, including 26 283 ML amplitude readings from 4 204 events recorded by 38 stations. The result is similar with previous research but has higher resolution. Estimated Q0 values are consistent with tectonic and topographic structure in North China. Q0 is low in the active tectonic regions having many faults, such as Bohai bay, North China basin, the Shanxi and Yinchuan grabens, while it is high in the stable Ordos craton. Q0 values are low in several topographically low-lying areas, such as the North China, Taikang-Hefei, and Subei-Huanghai Sea basins, whereas it is high in mountainous and uplift regions exhibiting surface expressions of crystalline basement rocks: the Yinshan, Yanshan, Taihang, Qinling and Dabie mountains, Luxi and Jiaoliao uplifts. Quality factor estimates are also consistent with Pn and Sn velocity patterns. High velocity values in general correspond with high Q0 and vice versa. This coincides with a common temperature influence in the crust and uppermost mantle.
Abstract:We have updated the lateral variations of the quality factor Q0 (Q at 1 Hz) beneath the crust of North China using ML amplitude tomography with near three times data. The data were selected from the Annual Bulletin of Chinese Earthquakes (ABCE) in 1985-2009, including 26 283 ML amplitude readings from 4 204 events recorded by 38 stations. The result is similar with previous research but has higher resolution. Estimated Q0 values are consistent with tectonic and topographic structure in North China. Q0 is low in the active tectonic regions having many faults, such as Bohai bay, North China basin, the Shanxi and Yinchuan grabens, while it is high in the stable Ordos craton. Q0 values are low in several topographically low-lying areas, such as the North China, Taikang-Hefei, and Subei-Huanghai Sea basins, whereas it is high in mountainous and uplift regions exhibiting surface expressions of crystalline basement rocks: the Yinshan, Yanshan, Taihang, Qinling and Dabie mountains, Luxi and Jiaoliao uplifts. Quality factor estimates are also consistent with Pn and Sn velocity patterns. High velocity values in general correspond with high Q0 and vice versa. This coincides with a common temperature influence in the crust and uppermost mantle.
基金资助:the Chinese Academy of Sciences (Grant No. KZCX2-EW-QN102) and the National Natural Science Foundation of China (Nos. 41074041, 90814002 and 40674031).
通讯作者:
Shunping Pei
E-mail: peisp@itpcas.ac.cn
引用本文:
Shunping Pei, Yongshun John Chen. The updated crustal attenuation in North China using ML amplitude tomography[J]. 《地震学报》英文版, 2010, 23(6): 541-548.
Shunping Pei, Yongshun John Chen. The updated crustal attenuation in North China using ML amplitude tomography. Earthquake Science, 2010, 23(6): 541-548.