Seismic clustering in the Sea of Marmara: Implications for monitoring earthquake processes
Seismic clustering in the Sea of Marmara: Implications for monitoring earthquake processes
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DOI：
10.1016/j.tecto.2019.228176
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发表时间：
2019-10-05
期刊：
影响因子：
2.9
通讯作者：
Bohnhoff, Marco
中科院分区：
文献类型：
--
作者：
Martinez-Garzon, Patricia;Ben-Zion, Yehuda;Bohnhoff, Marco
量化区域地震群类型对于为地震活动模式和地震相互作用的研究提供背景至关重要。在这里，我们使用最近得出的高分辨率地震活动目录和最近邻地震群方法，识别了土耳其西北部北安纳托利亚断层马尔马拉海地区的地震活动群。检测到的地震群用于（1）确定主震和余震频率的空间分布并估计不同断层段上的破坏接近程度，（2）识别具有地震重复的断层部分，以及（3）查找前震活动增强的区域。约 6%、70% 和 24% 的事件分别被确定为前震、主震和余震，其中余震和前震最集中的区域分别位于西部高地和西纳尔西克断层沿线。该方法成功地识别了先前研究报告的地震重复区域作为断层蠕变的指标，并建议在盖姆利克湾增加额外的重复区域。伴随前震和余震的主震比例最大的地区是西部高断层断层和奇纳西克断层，这可能表明这些断层更接近破坏，并且对地震触发的敏感性增加。持续研究有助于监测伊斯坦布尔大都市区附近马尔马拉地区大地震（M > 7）可能的准备阶段。
Quantifying regional earthquake cluster style is essential for providing a context for studies of seismicity patterns and earthquake interactions. Here, we identify clusters of seismicity in the Sea of Marmara region of the North Anatolian Fault, NW Turkey, using a recently derived high-resolution seismicity catalog and the nearest-neighbor earthquake cluster approach. The detected earthquake clusters are utilized for (1) determining spatial distribution of mainshock and aftershock rates and estimating the proximity to failure on different fault segments, (2) identifying fault sections having earthquake repeaters, and (3) finding areas with enhanced foreshock activity. About 6%, 70% and 24% of the events are identified as foreshocks, mainshocks and aftershocks, respectively, with the largest concentration of aftershocks and foreshocks located along the Western High and the Cinarcik Fault, respectively. The method successfully identifies regions where previous studies reported earthquake repeaters as indicator for fault creep and suggests additional repeater areas in the Gulf of Gemlik. The largest proportion of mainshocks with associated foreshocks and aftershocks are along the Western High and Cinarcik Fault segments, potentially indicating that these segments are closer to failure and have increased susceptibility to seismic triggering. Continuing studies can contribute to monitoring possible preparation phase of a large (M > 7) earthquake in the Marmara region near the Istanbul Metropolitan region.