Variations in the Characteristic Amplitude of Tectonic Tremor Induced by Long‐Term Slow Slip Events
Variations in the Characteristic Amplitude of Tectonic Tremor Induced by Long‐Term Slow Slip Events
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长期慢滑事件诱发的构造震颤特征幅度变化
DOI：
10.1029/2020jb021138
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Mizukami Tomoyuki
中科院分区：
文献类型：
--
作者：
Nakamoto Keita;Hiramatsu Yoshihiro;Matsuzawa Takanori;Mizukami Tomoyuki
长期慢滑事件（L‐sse）经常激发短期慢滑事件（S‐sse）和幕式震颤和滑动带（ETS）的构造震颤。然而，控制原发性和兴奋性震颤事件发生的因素尚不清楚。为了阐明这些因素，我们分析了Bungo海峡（南开俯冲带）及其周围的构造震颤事件，在那里已知L‐sse激发了ETS带的震颤和S‐sse。我们关注震颤的特征振幅（CA）的空间分布，由震颤事件的持续时间-振幅分布确定，作为震颤源性质的指标。在L - SSE滑动区，ca较大，而在邻近区域则较小。在震颤激发期（L‐sse）和间隔期（ΔCA） CA值的差值在滑移区为正，在相邻区域为负，在远场趋向于零。我们认为CA和ΔCA的非均匀分布反映了震颤斑块的非均匀有效强度，这可能分别与岩石学性质以及L‐sse引起的应力和孔隙流体压力变化有关。从ETS区沿板块界面向上运移的流体可能会调节L‐SSEs期间震颤斑块的有效应力和强度状态。
Long‐term slow slip events (L‐SSEs) often excite short‐term slow slips events (S‐SSEs) and tectonic tremor in the zone of episodic tremor and slip (ETS). However, the factors controlling the occurrence of primary versus excited tremor events remain unclear. To elucidate these factors, we analyzed tectonic tremor events in and around the Bungo Channel (Nankai subduction zone), where L‐SSEs are known to excite tremor and S‐SSEs in the ETS zone. We focused on the spatial distribution of the characteristic amplitude (CA) of tremor, determined from the duration‐amplitude distributions of tremor events, as an indicator of the properties of the tremor source. CAs are large in L‐SSE slip areas and small in adjacent areas. The difference between CA values during tremor‐excitation periods (L‐SSEs) and the intervening periods (ΔCA) is positive in the slip area, negative in adjacent areas, and tends toward zero in the far field. We suggest that the heterogeneous distributions of CA and ΔCA reflect the heterogeneous effective strengths of tremor patches, which might be related to petrological properties, and stress and pore‐fluid pressure variations induced by L‐SSEs, respectively. The upward migration of fluid from the ETS zone along the plate interface might modulate the effective stress and strength states of tremor patches during L‐SSEs.
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影响因子：
56.9
作者：
Ozawa, S;Murakami, M;Nishimura, T
通讯作者：
Nishimura, T
俯冲带构造震动地震能量率空间分布
影响因子：
--
作者：
K. Sadakane;Y. Horikawa;M. Nagao;and H. Seto;S. Yabe and S. Ide
通讯作者：
S. Yabe and S. Ide
日本四国深部低频地震估计的短期慢滑移事件特征
影响因子：
--
作者：
T. Hirose;Y. Hiramatsu;K. Obara
通讯作者：
K. Obara
影响因子：
5.2
作者：
Obara, Kazushige;Tanaka, Sachiko;Matsuzawa, Takanori
通讯作者：
Matsuzawa, Takanori
墨西哥瓦哈卡下方俯冲界面的板间耦合和瞬态滑移
影响因子：
2.8
作者：
F. Correa;C. Demets;E. Cabral;B. Márquez;O. Diaz
通讯作者：
O. Diaz