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Characterization of Microseismic Noise in Cape Verde

2019; Seismological Society of America; Volume: 109; Issue: 3 Linguagem: Inglês

10.1785/0120180291

1943-3573

Joana Carvalho, Graça Silveira, Martín Schimmel, É. Stutzmann,

Seismology and Earthquake Studies

Research Article| May 07, 2019 Characterization of Microseismic Noise in Cape Verde Joana F. Carvalho; Joana F. Carvalho Corresponding Author aInstituto Dom Luiz, Edificio C8, FCUL, Campo Grande, 1749‐016 Lisbon, Portugal, jfcarvalho@fc.ul.ptmdsilveira@fc.ul.ptdAlso at Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749‐016 Lisbon, Portugal. Search for other works by this author on: GSW Google Scholar Graça Silveira; Graça Silveira aInstituto Dom Luiz, Edificio C8, FCUL, Campo Grande, 1749‐016 Lisbon, Portugal, jfcarvalho@fc.ul.ptmdsilveira@fc.ul.pteAlso at Instituto Superior de Engenharia de Lisboa, Rua Rua Conselheiro Emídio Navarro 1, 1959‐007 Lisbon, Portugal. Search for other works by this author on: GSW Google Scholar Martin Schimmel; Martin Schimmel bInstitute of Earth Sciences Jaume Almera, C/ Lluis Solé Sabaris s/n, E‐08028 Barcelona, Spain, schimmel@ictja.csic.es Search for other works by this author on: GSW Google Scholar Eleonore Stutzmann Eleonore Stutzmann cSeismology Group (Office 302), Institut de Physique du Globe de Paris, 1 rue Jussieu, 75252 Paris, Cedex 5, France, stutz@ipgp.fr Search for other works by this author on: GSW Google Scholar Author and Article Information Joana F. Carvalho Corresponding Author aInstituto Dom Luiz, Edificio C8, FCUL, Campo Grande, 1749‐016 Lisbon, Portugal, jfcarvalho@fc.ul.ptmdsilveira@fc.ul.ptdAlso at Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749‐016 Lisbon, Portugal. Graça Silveira aInstituto Dom Luiz, Edificio C8, FCUL, Campo Grande, 1749‐016 Lisbon, Portugal, jfcarvalho@fc.ul.ptmdsilveira@fc.ul.pteAlso at Instituto Superior de Engenharia de Lisboa, Rua Rua Conselheiro Emídio Navarro 1, 1959‐007 Lisbon, Portugal. Martin Schimmel bInstitute of Earth Sciences Jaume Almera, C/ Lluis Solé Sabaris s/n, E‐08028 Barcelona, Spain, schimmel@ictja.csic.es Eleonore Stutzmann cSeismology Group (Office 302), Institut de Physique du Globe de Paris, 1 rue Jussieu, 75252 Paris, Cedex 5, France, stutz@ipgp.fr Publisher: Seismological Society of America First Online: 07 May 2019 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2019) 109 (3): 1099–1109. https://doi.org/10.1785/0120180291 Article history First Online: 07 May 2019 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Joana F. Carvalho, Graça Silveira, Martin Schimmel, Eleonore Stutzmann; Characterization of Microseismic Noise in Cape Verde. Bulletin of the Seismological Society of America 2019;; 109 (3): 1099–1109. doi: https://doi.org/10.1785/0120180291 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract The interaction of ocean waves with either the seafloor or other ocean waves generates primary (PM) and secondary microseisms (SM) that propagate through the crust and mantle, predominantly as Rayleigh waves. The horseshoe geometry and surrounding bathymetry of the Cape Verde archipelago play a significant role in the ambient‐noise generation in this region. We analyze the microseisms recorded in the region using two different temporary seismic networks, and we determine the number of signals polarized as Rayleigh waves and their back azimuth (BAZ) as a function of time and frequency. The relative number of polarized signals between PM and SM varies between the stations. At most of the stations, the SM can be divided into two frequency bands. At lower frequencies (0.1–0.2 Hz), the number of SM signals is stable throughout the year, whereas at higher frequencies (0.2–0.3 Hz) this number varies with the season, with more polarized signals during the northern hemisphere spring and summer. In both frequency ranges and at most stations, the BAZ does not vary significantly over the year and points toward sources within the archipelago and outside. We compute the source site effect and show that the local bathymetry around the Cape Verde Islands strongly amplifies local SM sources. Finally, we compare the measured BAZ with source areas derived from an ocean‐wave model, which confirms that Cape Verde stations mostly record local sources. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.