Five Short Historical Earthquake Surface Ruptures near the Silk Road, Gansu Province, China
Five Short Historical Earthquake Surface Ruptures near the Silk Road, Gansu Province, China
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DOI：
10.1785/0120080282
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发表时间：
2010-04
影响因子：
3
通讯作者：
Xi-wei Xu;R. Yeats;Gui-hua Yu
中科院分区：
文献类型：
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作者：
Xi-wei Xu;R. Yeats;Gui-hua Yu
自公元180年以来，青藏高原东北缘的河西走廊沿线沿着共发生了5次7级以上地震。它们分别是公元180年高台7.5级地震、1609年红崖子7.25级地震、1927年古浪8.0级地震、1932年昌马7.6级地震和1954年山丹7.3级地震。除1932年昌马地震和1954年山丹地震外，其余地震均以逆滑为主。昌马地震的特征是左旋活动带反向分量，山丹地震的特征是右旋活动带正向分量。现场调查表明，公元180年地震的地表破裂带长度仅为28km，1609年地震为11km，1927年地震为23km，1954年地震为5.1km，比用矩震级（Mw）、地表破裂长度（SRL）、同震位移（D）、最大位移（MD）、平均位移（AD）和模态值联合位移统计量（MVCDS）：走滑断层为Mw5：91：0：609 logSRL × D，逆断层为Mw5：81：0：653 logSRL × D，所有断层为Mw6：93：0：82 logAD × MVCDS。这可能是常见的逆断层地震在世界范围内，并建议，试图估计过去地震的震级从一种类型的，即使是最近的地表破裂数据是不可靠的和震级之间的经验公式，同震滑动，地表破裂长度应谨慎应用于地震危险性评估活动逆冲断层。
Five historical earthquakes (M ≥7) have occurred along the Hexi Corridor at the northeastern margin of the Tibetan Plateau since A.D. 180. These are the A.D. 180 Gaotai earthquake (M 7.5), the 1609 Hongyazi earthquake (M 7.25), the 1927 Gulang earthquake (M 8.0), the 1932 Changma earthquake (M 7.6), and the 1954 Shandan earthquake (M 7.3). They are predominantly reverse slip, except for the 1932 Changma and the 1954 Shandan earthquakes. The Changma earthquake is char- acterized by left-lateral faulting with a reverse component, while the Shandan earth- quake by right-lateral faulting with a normal component. Fieldinvestigationsindicatethatthelengthofthesurface-rupturezoneisonly28km for the A.D. 180 earthquake, 11 km for the 1609 earthquake, 23 km for the 1927 earth- quake, and 5.1 km for the 1954 earthquake, much shorter than that predicted using an empirical equation between moment magnitude (Mw), surface-rupture length (SRL), coseismic displacement (D), maximum displacement (MD), average displacement (AD), and mode value combined displacement statistic (MVCDS): Mw � 5:91� 0:609logSRL × Dfor strike-slip faults, Mw � 5:81 � 0:653logSRL × Dfor reverse faults, and Mw � 6:93 � 0:82logAD × MVCDSfor all faults. This may be common for reverse faulting earthquakes worldwide and suggests that trying to estimate magnitudes of past earthquakes from one type of even the most recent surface-rupture data is unreliable and the empirical equations between magnitude, coseismic slip, and surface-rupture length should be applied with caution to seismic hazard assessment on active thrust faults.