Continuous Tremor Activity With Stable Polarization Direction Following the 2014 Large Slow Slip Event in the Hikurangi Subduction Margin Offshore New Zealand
Continuous Tremor Activity With Stable Polarization Direction Following the 2014 Large Slow Slip Event in the Hikurangi Subduction Margin Offshore New Zealand
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继 2014 年新西兰近海希库朗伊俯冲边缘大型慢滑移事件之后，具有稳定极化方向的持续震颤活动
DOI：
10.1029/2021jb022161
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Shinohara Masanao
中科院分区：
文献类型：
--
作者：
Iwasaki Yuriko;Mochizuki Kimihiro;Ishise Motoko;Todd Erin K.;Schwartz Susan Y.;Zal Hubert;Savage Martha K.;Henrys Stuart;Sheehan Anne F.;Ito Yoshihiro;Wallace Laura M.;Webb Spahr C.;Yamada Tomoaki;Shinohara Masanao
在世界各地的俯冲带已经发现了许多类型的慢地震。然而，这些慢地震的物理过程还没有得到很好的理解。为了监测近海慢地震，2014年5月至2015年6月在希库朗吉俯冲边缘进行了海洋地震和大地测量实验。在这个实验中，一个大的慢滑事件（Mw 6.8）发生在海底地震仪（OBS）网络的正下方。在这项研究中，S波分裂和极化分析方法，这是以前使用的陆上数据调查震颤和各向异性，应用于连续的OBS波形数据，以识别震颤太小，无法检测的包络互相关方法。在2014年慢滑事件结束时检测到具有稳定极化方向的连续震颤活动，并持续约2周。震颤产生于缓慢滑动等高线的西南弯曲周围和俯冲海山的向陆边缘。我们的研究结果证实了以前的解释，基于突发型重复地震和间歇性震颤，海山周围的局部缓慢滑动和震颤是由大板块边界缓慢滑动事件后的流体迁移引发的，并表明震颤连续发生，而不是孤立和零星的个别事件。
Many types of slow earthquakes have been discovered at subduction zones around the world. However, the physical process of these slow earthquakes is not well understood. To monitor offshore slow earthquakes, a marine seismic and geodetic experiment was conducted at the Hikurangi subduction margin from May 2014 to June 2015. During this experiment, a large slow slip event (Mw 6.8) occurred directly beneath the ocean bottom seismometer (OBS) network. In this study, S‐wave splitting and polarization analysis methods, which have been previously used on onshore data to investigate tremor and anisotropy, are applied to continuous OBS waveform data to identify tremors that are too small to detect by the envelope cross correlation method. Continuous tremor activity with stable polarization directions is detected at the end of the 2014 slow slip event and continued for about 2 weeks. The tremors are generated around a southwest bend in the slow slip contours and at the landward edge of a subducted seamount. Our findings corroborate a previous interpretation, based on burst‐type repeating earthquakes and intermittent tremor, that localized slow slip and tremor around the seamount was triggered by fluid migration following the large plate boundary slow slip event and indicate tremor occurred continuously rather than as isolated and sporadic individual events.
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使用校正各向异性影响的 S 波偏振数据确定非火山震颤的震源机制
影响因子：
5.2
作者：
K. Imanishi;T. Uchide;N. Takeda
通讯作者：
N. Takeda
DOI：
10.1029/2020jb020810
发表时间：
2021-02
期刊：
Journal of Geophysical Research: Solid Earth
影响因子：
--
作者：
J. Nakai;A. Sheehan;R. Abercrombie;D. Eberhart‐Phillips
通讯作者：
J. Nakai;A. Sheehan;R. Abercrombie;D. Eberhart‐Phillips
影响因子：
5.2
作者：
Barker, Daniel H. N.;Henrys, Stuart;Wallace, Laura
通讯作者：
Wallace, Laura
影响因子：
2.8
作者：
Bell, Rebecca;Sutherland, Rupert;Beavan, John
通讯作者：
Beavan, John
影响因子：
56.9
作者：
Mochizuki, Kimihiro;Yamada, Tomoaki;Kanazawa, Toshihiko
通讯作者：
Kanazawa, Toshihiko