| Autor: |
Fan, Wenyuan, McGuire, Jeffrey J., Groot‐Hedlin, Catherine D., Hedlin, Michael A. H., Coats, Sloan, Fiedler, Julia W. |
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| Zdroj: |
Geophysical Research Letters; 11/28/2019, Vol. 46 Issue 22, p12909-12918, 10p |
| Abstrakt: |
Seismic signals from ocean‐solid Earth interactions are ubiquitously recorded on our planet. However, these wavefields are typically incoherent in the time domain limiting their utilization for understanding ocean dynamics or solid Earth properties. In contrast, we find that during large storms such as hurricanes and Nor'easters the interaction of long‐period ocean waves with shallow seafloor features located near the edge of continental shelves, known as ocean banks, excites coherent transcontinental Rayleigh wave packets in the 20‐ to 50‐s period band. These "stormquakes" migrate coincident with the storms but are effectively spatiotemporally focused seismic point sources with equivalent earthquake magnitudes that can be greater than 3.5. Stormquakes thus provide new coherent sources to investigate Earth structure in locations that typically lack both seismic instrumentation and earthquakes. Moreover, they provide a new geophysical observable with high spatial and temporal resolution with which to investigate ocean wave dynamics during large storms. Plain Language Summary: Large storms such as hurricanes and Nor'easters generate strong long‐period ocean waves, which can interact with shallow seafloor features located near the edge of continental shelves known as ocean banks. Such interactions produce seismic sources with equivalent earthquake magnitudes that can be greater than 3.5. These seismic sources are termed "stormquakes," and they can excite coherent seismic wave fields that are well recorded across the North American continent. Stormquake is a newly identified geophysical phenomenon, which involves interactions of atmosphere, ocean, and the solid Earth. Therefore, stormquakes can provide useful information to investigate the Earth structure and ocean wave dynamics. Key Points: Energetic storms can generate stormquakes exciting coherent transcontinental surface wavefieldsThese stormquakes are effective point sources with equivalent earthquake magnitudes that can be greater than 3.5Large continental shelves, ocean banks, and strong storms are the three necessary factors for stormquake generation [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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