The Pawnee earthquake as a result of the interplay among injection, faults and foreshocks.
The Pawnee earthquake as a result of the interplay among injection, faults and foreshocks.
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DOI：
10.1038/s41598-017-04992-z
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发表时间：
2017-07-10
影响因子：
4.6
通讯作者：
Walter JI
中科院分区：
文献类型：
--
作者：
Chen X;Nakata N;Pennington C;Haffener J;Chang JC;He X;Zhan Z;Ni S;Walter JI
波尼 M5.8 地震是俄克拉荷马州仪器记录历史上最大的事件。它发生在活跃地震带的边缘附近，与 2011 年以来的其他 M5+ 地震类似。它破裂了先前未绘制地图的断层，并沿着复杂的共轭断层系统引发了余震。通过高分辨率地震目录，我们观察到传播的前震导致 0.5 公里范围内的主震，这表明存在前兆地震滑移。在主震发生前大约 100 天，沿着与主震断层共轭的映射断层发生了两次 M ≥ 3.5 级地震。大约40天前，发生了两次地震群，其中一次M3地震发生在主震前两天。 3次M ≥ 3级前震均在主震震源处产生正库仑应力。共轭断层系统内的这些前震活动几乎是瞬时响应注入率的变化（置信度为 95%）。注入和地震活动之间的短时延不同于假设的扩散过程的预期时间尺度和2016年之前在该地区观察到的长时延，这表明弹性应力传递和断层临界应力状态可能发挥作用。我们的结果表明，波尼地震是注入、构造断层和前震相互作用的结果。
The Pawnee M5.8 earthquake is the largest event in Oklahoma instrument recorded history. It occurred near the edge of active seismic zones, similar to other M5+ earthquakes since 2011. It ruptured a previously unmapped fault and triggered aftershocks along a complex conjugate fault system. With a high-resolution earthquake catalog, we observe propagating foreshocks leading to the mainshock within 0.5 km distance, suggesting existence of precursory aseismic slip. At approximately 100 days before the mainshock, two M ≥ 3.5 earthquakes occurred along a mapped fault that is conjugate to the mainshock fault. At about 40 days before, two earthquakes clusters started, with one M3 earthquake occurred two days before the mainshock. The three M ≥ 3 foreshocks all produced positive Coulomb stress at the mainshock hypocenter. These foreshock activities within the conjugate fault system are near-instantaneously responding to variations in injection rates at 95% confidence. The short time delay between injection and seismicity differs from both the hypothetical expected time scale of diffusion process and the long time delay observed in this region prior to 2016, suggesting a possible role of elastic stress transfer and critical stress state of the fault. Our results suggest that the Pawnee earthquake is a result of interplay among injection, tectonic faults, and foreshocks.
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影响因子：
3.9
作者：
DIETERICH, J
通讯作者：
DIETERICH, J
影响因子：
3.9
作者：
Chang, K. W.;Segall, P.
通讯作者：
Segall, P.
影响因子：
3.3
作者：
Barbour, Andrew J.;Crowell, Brendan W.
通讯作者：
Crowell, Brendan W.
影响因子：
3.5
作者：
Elebiju, Olubunmi O.;Matson, Shane;Marfurt, Kurt J.
通讯作者：
Marfurt, Kurt J.
影响因子：
56.9
作者：
HEALY, JH;RUBEY, WW;RALEIGH, CB
通讯作者：
RALEIGH, CB