基于GPS数据的海原-六盘山断裂带滑动速率亏损时空分布

发布时间：2018-05-19 03:13

本文选题：海原-六盘山断裂带 + 闭锁　；参考：《地震地质》2017年03期

【摘要】：利用青藏高原东北缘及周缘地区1999—2007年和2009—2014年2个时段的GPS水平运动速度场做约束,反演获取了海原-六盘山断裂带的闭锁程度和滑动速率亏损的时空分布演化。结果表明,海原断裂带以左旋走滑亏损为主,六盘山断裂北段以逆冲倾滑速率亏损为主,南段则以正向倾滑为主。其中,毛毛山断裂和老虎断裂西段在2个时段的闭锁深度都达到25km,最大左旋滑动亏损为6mm/a。老虎山东段和海原断裂(狭义)闭锁程度低,主要处于蠕滑状态。六盘山断裂2个时段的闭锁深度可达35km,最大逆冲滑动速率亏损为2mm/a。汶川地震后,六盘山断裂上逆冲滑动速率亏损高值区由中段迁移至北段且范围减小,南段则变成正倾滑速率亏损。毛毛山、老虎山西段和六盘山断裂的地震危险性要明显高于海原-六盘山断裂带其他断层段。
[Abstract]:Based on the GPS horizontal velocity field in the northeastern margin of the Qinghai-Xizang Plateau from 1999 to 2007 and from 2009 to 2014, the temporal and spatial distributions of the blocking degree and the slip rate deficit of the Haiyuan-Liupanshan fault zone are obtained. The results show that the fault zone of Haiyuan is dominated by left-lateral strike-slip deficit, the northern segment of Liupanshan fault is dominated by thrust-dip slip rate, and the southern segment is dominated by positive dip slip. The western segment of the Maomaoshan fault and the Tiger fault have both 25 km of atresia depth and the maximum left-hand slip deficit is 6 mm / a. The tiger-Shandong segment and Haiyuan fault (narrow sense) have low locking degree and are mainly in creeping state. The locking depth of Liupanshan fault in two periods can reach 35 km and the maximum slip rate deficit is 2 mm / a. After the Wenchuan earthquake, the high value region of the upper thrust slip rate deficit of Liupanshan fault migrated from the middle to the north segment and the range decreased, while the southern segment became the normal dip slip rate deficit. The seismic risk of Maomaoshan, Tiaoxian and Liupanshan faults is obviously higher than that of other fault sections of Haiyuan-Liupanshan fault zone.
【作者单位】：中国地震局第二监测中心;
【基金】：地震行业科研重大专项(201508009) 国家自然科学基金(41590861)共同资助
【分类号】：P315.2

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