The 2017–2018 Maple Creek Earthquake Sequence in Yellowstone National Park, USA
The 2017–2018 Maple Creek Earthquake Sequence in Yellowstone National Park, USA
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2017-2018年美国黄石国家公园枫树溪地震序列
DOI：
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发表时间：
2019
影响因子：
5.2
通讯作者：
Robert B. Smith
中科院分区：
文献类型：
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作者：
G. Pang;K. Koper;J. Hale;R. Burlacu;J. Farrell;Robert B. Smith
我们探索了2017年6月12日至2018年3月13日在黄石公园枫树溪附近发生的3345次地震的详细时空演化。我们利用440万个P波和由波形互相关得到的S波差分走时，产生了高精度的重新定位和近源VP/VS比。震源在地理上可细分为两个主要亚群：北部群主要为NW-SE向平面构造，南部群为以东西向为主的平面构造群。北部群的Vp/VS比值为1.39-1.66，南部群的Vp/VS值稳定在1.50，表明存在充填CO2的裂隙。我们将北部震群主要解释为1959年海布根湖7.2级地震的长期余震，但也有一些岩浆流体的影响。我们将南部地震群解释为主要由岩浆流体迁移引起的更经典的群状序列。
We explore the detailed spatiotemporal evolution of 3,345 earthquakes that occurred near Maple Creek, Yellowstone, for the time period of 12 June 2017 to 13 March 2018. We generate high‐accuracy relocations and near source VP/VS ratios using 4.4 million P wave and S wave differential travel times derived from waveform cross correlation. The hypocenters can be subdivided geographically into two major subpopulations: a northern cluster with planar structures striking mainly NW‐SE and a southern cluster with planar structures striking mainly E‐W. We observe VP/VS ratios of 1.39–1.66 in the northern cluster and a steady ratio of 1.50 in the southern cluster, suggesting the presence of CO2‐filled cracks. We interpret the northern earthquake cluster primarily as long‐lived aftershocks of the 1959 Mw 7.2 Hebgen Lake earthquake but with some influence of magmatic fluids. We interpret the southern earthquake cluster as a more classic, swarm‐like sequence induced primarily by the migration of magmatic fluids.