Migrating tremor off southern Kyushu as evidence for slow slip of a shallow subduction interface
Migrating tremor off southern Kyushu as evidence for slow slip of a shallow subduction interface
复制标题
DOI：
10.1126/science.aaa4242
复制
发表时间：
2015-05
期刊：
影响因子：
56.9
通讯作者：
著者Yusuke Yamashita;H. Yakiwara;Y. Asano;Hiroshi Shimizu;K. Uchida;S. Hirano;K. Umakoshi;H. Miyamachi;M. Nakamoto;Miyo Fukui;Megumi Kamizono;Hisao Kanehara;Tomoaki Yamada;M. Shinohara;K. Obara
中科院分区：
文献类型：
--
作者：
著者Yusuke Yamashita;H. Yakiwara;Y. Asano;Hiroshi Shimizu;K. Uchida;S. Hirano;K. Umakoshi;H. Miyamachi;M. Nakamoto;Miyo Fukui;Megumi Kamizono;Hisao Kanehara;Tomoaki Yamada;M. Shinohara;K. Obara
无声滑动事件得到浅层线索，以帮助更好地预测毁灭性地震和海啸的可能性，可能会嵌入到更温和的隆隆声中。Yamashita等人使用海底地震仪报告了在日本九州南部俯冲带的浅部罕见的迁移性震颤观测结果。这些震动似乎与一次非常低频的地震有关，而且似乎会迁移到发生大地震的地区。这些震动可能是在追踪应力是如何以及在哪里集中到断层的地震发生部分的。地震和海啸灾害预测可能受益于俯冲带地震震颤迁移的浅层观测。浅层慢地震的探测提供了对俯冲界面的近海沟部分的深入了解，这是大地震破裂和海啸产生的重要区域。对日本九州南部近海地震活动的海底监测记录了一个完整的低频震颤事件，持续了1个月，这与浅板块界面的甚低频地震活动有关。浅震发作表现出两种迁移模式，让人想起深震下倾的孕震区在其他一些俯冲带：一个大规模的较慢的传播模式和快速反转模式。这些迁移特性的相似性和与VLFE的关联强烈表明，浅、深地震和VLFE都可能是由幕式慢滑事件的迁移触发的。
Silent slip events get shallow Clues to help better predict the likelihood of devastating earthquakes and tsunamis may be embedded in a more gentle type of rumbling. Using oceanbottom seismometers, Yamashita et al. report rare observations of migrating tremors in the shallow part of a subduction zone off southern Kyushu, Japan. The tremors appear to be linked to a very low-frequency earthquake and seem to migrate to the region where big earthquakes are generated. The tremors may be tracing how and where stress gets concentrated onto the earthquake-producing portion of the fault. Science, this issue p. 676 Earthquake and tsunami hazard forecasts may benefit from shallow observations of seismic tremor migration in subduction zones. Detection of shallow slow earthquakes offers insight into the near-trench part of the subduction interface, an important region in the development of great earthquake ruptures and tsunami generation. Ocean-bottom monitoring of offshore seismicity off southern Kyushu, Japan, recorded a complete episode of low-frequency tremor, lasting for 1 month, that was associated with very-low-frequency earthquake (VLFE) activity in the shallow plate interface. The shallow tremor episode exhibited two migration modes reminiscent of deep tremor down-dip of the seismogenic zone in some other subduction zones: a large-scale slower propagation mode and a rapid reversal mode. These similarities in migration properties and the association with VLFEs strongly suggest that both the shallow and deep tremor and VLFE may be triggered by the migration of episodic slow slip events.