Onset of aseismic creep on major strike-slip faults
Onset of aseismic creep on major strike-slip faults
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DOI：
10.1130/g33522.1
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发表时间：
2012-12
期刊：
影响因子：
5.8
通讯作者：
Z. Çakır;S. Ergintav;H. Ozener;U. Doğan;Ahmet M. Akoğlu;M. Meghraoui;R. Reilinger
中科院分区：
文献类型：
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作者：
Z. Çakır;S. Ergintav;H. Ozener;U. Doğan;Ahmet M. Akoğlu;M. Meghraoui;R. Reilinger
星载合成孔径雷达(SAR)数据的时间序列分析、GPS测量和野外观测表明，伊兹米特(土耳其)断裂的中段在公元1999年(Mw 7.4)以超剪切破裂速度滑动，地震后开始无震地蠕动。最初的震后快速余滑随时间呈对数衰减，似乎已达到与震前完全断层交叉率相当的稳定速率，表明这种情况可能会持续数十年，可能会持续到地震周期的末期。如果被未来的监测所证实，这些观测确定了震后余滑是沿着走滑断层启动蠕变行为的机制。长期的余滑和/或蠕变对地震周期模型、大地震的重复间隔以及相应的成熟走滑断层的地震危险性估计具有重要意义，特别是对于伊斯坦布尔，它被认为位于马尔马拉海北安纳托利亚断层地震空区附近。
Time series analysis of spaceborne synthetic aperture radar (SAR) data, GPS measurements, and field observations reveal that the central section of the Izmit (Turkey) fault that slipped with a supershear rupture velocity in the A.D. 1999, M w 7.4, Izmit earthquake began creeping aseismically following the earthquake. Rapid initial postseismic afterslip decayed logarithmically with time and appears to have reached a steady rate comparable to the pre-earthquake full fault-crossing rate, suggesting that it may continue for decades and possibly until late in the earthquake cycle. If confirmed by future monitoring, these observations identify postseismic afterslip as a mechanism for initiating creep behavior along strike-slip faults. Long-term afterslip and/or creep has significant implications for earthquake cycle models, recurrence intervals of large earthquakes, and accordingly, seismic hazard estimation along mature strike-slip faults, in particular for Istanbul which is believed to lie adjacent to a seismic gap along the North Anatolian fault in the Sea of Marmara.