Analyses of extreme swell events on La Réunion Island from microseismic noise
| Autor: | Guilhem Barruol, Fabrice R. Fontaine, Céline Davy, Emmanuel Cordier |
|---|---|
| Přispěvatelé: | Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Observatoire des Sciences de l'Univers de La Réunion (OSU-Réunion), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR), ANR-11-BS56-0013,RHUM-RUM,Imagerie mantellique du point chaud de La Réunion(2011), Institut de Physique du Globe de Paris-Université de La Réunion (UR), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
La Réunion Island
010504 meteorology & atmospheric sciences broad-band seismometers [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] 010502 geochemistry & geophysics 01 natural sciences Seismic wave Geochemistry and Petrology Wind wave Microseismic noise tropical cyclones 14. Life underwater Indian Ocean 0105 earth and related environmental sciences primary microseisms Microseism swell Buoy surface waves Swell Geophysics 13. Climate action Surface wave Cyclone Tropical cyclone secondary microseisms Seismology Geology |
| Zdroj: | Geophysical Journal International Geophysical Journal International, Oxford University Press (OUP), 2016, 207 (3), pp.1767-1782. ⟨10.1093/gji/ggw365⟩ |
| ISSN: | 0956-540X 1365-246X |
| Popis: | International audience; Ocean wave activity excites seismic waves that propagate through the solid earth, known as microseisms, which, once recorded on oceanic islands, can be used to analyze the swell. Here, we analyze the microseismic noise recorded in different period ranges by the permanent seismic station RER on La Réunion Island and by a temporary network of ten broad-band seismic stations deployed on the island to analyze extreme swell events. We perform a comparative analysis of cyclonic and austral swell events by analyzing the primary (PM, ∼ 10 to 20 s period) and secondary (SM, ∼ 3 to 10 s) microseisms, but also the long period secondary microseisms (LPSM, ∼ 7 to 10 s), which may result from the interaction between incident ocean waves and the reflected waves off the coast. We compare the microseismic observations with buoy data when available and with predictions from numerical ocean wave models. We show that each cyclone is characterized by its own individual signature in the SM, which depends on its distance and intensity, but also on its dynamics and trajectory. Thus, the SM contains relevant information for cyclone detection and monitoring. Analyzing the PM and the LPSM, and comparing it to direct buoy observations and/or swell numerical models allows characterizing the local impact of the swell with the island in terms of amplitude, period, and sometimes, direction of propagation, making possible to use a seismic station as an ocean wave gauge. The microseisms, which link the atmosphere, the ocean and the solid Earth, can thus provide valuable observations on extreme swells, in addition to oceanic and meteorological data. |
| Databáze: | OpenAIRE |
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