Toward High‐Resolution Period‐Dependent Seismic Monitoring of Tropical Cyclones. Issue 3 (12th February 2019)

• Record Type: Journal Article
• Authors: Retailleau, Lise; Gualtieri, Lucia
• Is Part Of: Geophysical research letters. Volume 46:Issue 3(2019)
• Page Start: 1329
• Page End: 1337
• Publication Date: 2019-02-12
• Subjects: body waves -- seismic instruments and networks -- tropical cyclones; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2018GL080785
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Pioneering work in the midtwentieth century laid the foundation for our understanding of secondary microseism generation by tropical cyclones. Yet, tracking their sources and linking them to the mechanisms that generate these signals remain challenging. Here, we successfully retrieve the seismic sources associated with Typhoon Ioke (2006) with an unprecedented 3‐hr resolution and in the entire secondary microseism period band ( T = 2–9 s). Our results indicate that the seismic sources follow the tropical cyclone at a constant distance from its center, corresponding to 34‐kt winds. We also assess the link between the generation of the long‐period secondary microseism signals and the increase of the typhoon propagation speed. This accurate location of seismic sources may provide a new data set for imaging the Earth's interior and allow for new insights on the interaction between the atmosphere, the ocean, and the solid Earth. Plain Language Summary: Tropical cyclones are most known for their direct impact on the population in terms of destructiveness and economic damage. In addition to satellites, which allow us to monitor these events from the sky, seismic sensors also record the signature of faraway tropical cyclones. Although several studies analyzed these signals, the relationship between these events and the seismic sources is not yet completely understood. In this study, we employ seismic signals recorded in California to track the location of a tropical cyclone in the Pacific Ocean with an unprecedented resolution. We extract the space and time relationship between the event and the seismic sources throughout the entire life cycle of the tropical cyclone. Hence, we infer novel findings on the generation of seismic signals due to tropical cyclones. This work is a step forward in the understanding of the relationship between the atmosphere, the ocean, and the solid Earth, and potentially toward getting novel constraints on the tropical cyclone activity in remote ocean basins and back in time. Key Points: Secondary microseism sources of a tropical cyclone are observed over its complete life cycle Seismic sources are located at a nearly constant distance from the center of the cyclone, corresponding to 34‐kt winds Secondary microseism sources at long period can only be observed when the tropical cyclone moves fast