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Wavefield Characteristics and Spatial Incoherency: A Comparative Study from Argostoli Rock‐ and Soil‐Site Dense Seismic Arrays

2018; Seismological Society of America; Volume: 108; Issue: 5A Linguagem: Inglês

10.1785/0120180025

1943-3573

Afifa Imtiaz, Vincent Perron, Fabrice Hollender, Pierre‐Yves Bard, Cécile Cornou, Angkeara Svay, Nikos Theodoulidis,

Seismic Imaging and Inversion Techniques

Research Article| July 24, 2018 Wavefield Characteristics and Spatial Incoherency: A Comparative Study from Argostoli Rock‐ and Soil‐Site Dense Seismic Arrays Afifa Imtiaz; Afifa Imtiaz aRisks and Prevention Division, Seismic and Volcanic Risks Unit, Bureau de Recherches Géologiques et Minières (BRGM), 3 Avenue Claude Guillemin, BP 36009, 45060 Orléans, CEDEX 2, France, a.imtiaz@brgm.fr Search for other works by this author on: GSW Google Scholar Vincent Perron; Vincent Perron bCEA, DEN, F‐13108 St Paul Lez Durance, CEDEX, France, vincent.perron.mail@gmail.comfabrice.hollender@cea.frfAlso at Univ. Grenoble Alpes, Univ. Savoie Mont‐Blanc, CNRS, IRD, IFSTTAR, ISTerre, Bâtiment OSUG C, CS 40700, 38058 Grenoble, CEDEX 9, France; IRSN, F‐92260 Fontenay‐aux‐Roses, France. Search for other works by this author on: GSW Google Scholar Fabrice Hollender; Fabrice Hollender bCEA, DEN, F‐13108 St Paul Lez Durance, CEDEX, France, vincent.perron.mail@gmail.comfabrice.hollender@cea.fr Search for other works by this author on: GSW Google Scholar Pierre‐Yves Bard; Pierre‐Yves Bard cUniv. Grenoble Alpes, Univ. Savoie Mont‐Blanc, CNRS, IRD, IFSTTAR, ISTerre, Bâtiment OSUG C, CS 40700, 38058 Grenoble, CEDEX 9, France, pierre-yves.bard@univ-grenoble-alpes.frcecile.cornou@univ-grenoble-alpes.fr Search for other works by this author on: GSW Google Scholar Cécile Cornou; Cécile Cornou cUniv. Grenoble Alpes, Univ. Savoie Mont‐Blanc, CNRS, IRD, IFSTTAR, ISTerre, Bâtiment OSUG C, CS 40700, 38058 Grenoble, CEDEX 9, France, pierre-yves.bard@univ-grenoble-alpes.frcecile.cornou@univ-grenoble-alpes.fr Search for other works by this author on: GSW Google Scholar Angkeara Svay; Angkeara Svay dInstitut des Sciences de la Mécanique et Applications Industrielles (IMSIA), University Paris‐Saclay, 91190 Saint‐Aubin, France, angkeara.svay@polytechnique.edu Search for other works by this author on: GSW Google Scholar Nikos Theodoulidis Nikos Theodoulidis eInstitute of Engineering Seismology and Earthquake Engineering (ITSAK), P.O. Box 53 Finikas, GR‐55102 Thessaloniki, Greece, ntheo@itsak.gr Search for other works by this author on: GSW Google Scholar Author and Article Information Afifa Imtiaz aRisks and Prevention Division, Seismic and Volcanic Risks Unit, Bureau de Recherches Géologiques et Minières (BRGM), 3 Avenue Claude Guillemin, BP 36009, 45060 Orléans, CEDEX 2, France, a.imtiaz@brgm.fr Vincent Perron bCEA, DEN, F‐13108 St Paul Lez Durance, CEDEX, France, vincent.perron.mail@gmail.comfabrice.hollender@cea.frfAlso at Univ. Grenoble Alpes, Univ. Savoie Mont‐Blanc, CNRS, IRD, IFSTTAR, ISTerre, Bâtiment OSUG C, CS 40700, 38058 Grenoble, CEDEX 9, France; IRSN, F‐92260 Fontenay‐aux‐Roses, France. Fabrice Hollender bCEA, DEN, F‐13108 St Paul Lez Durance, CEDEX, France, vincent.perron.mail@gmail.comfabrice.hollender@cea.fr Pierre‐Yves Bard cUniv. Grenoble Alpes, Univ. Savoie Mont‐Blanc, CNRS, IRD, IFSTTAR, ISTerre, Bâtiment OSUG C, CS 40700, 38058 Grenoble, CEDEX 9, France, pierre-yves.bard@univ-grenoble-alpes.frcecile.cornou@univ-grenoble-alpes.fr Cécile Cornou cUniv. Grenoble Alpes, Univ. Savoie Mont‐Blanc, CNRS, IRD, IFSTTAR, ISTerre, Bâtiment OSUG C, CS 40700, 38058 Grenoble, CEDEX 9, France, pierre-yves.bard@univ-grenoble-alpes.frcecile.cornou@univ-grenoble-alpes.fr Angkeara Svay dInstitut des Sciences de la Mécanique et Applications Industrielles (IMSIA), University Paris‐Saclay, 91190 Saint‐Aubin, France, angkeara.svay@polytechnique.edu Nikos Theodoulidis eInstitute of Engineering Seismology and Earthquake Engineering (ITSAK), P.O. Box 53 Finikas, GR‐55102 Thessaloniki, Greece, ntheo@itsak.gr Publisher: Seismological Society of America First Online: 24 Jul 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (5A): 2839–2853. https://doi.org/10.1785/0120180025 Article history First Online: 24 Jul 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Afifa Imtiaz, Vincent Perron, Fabrice Hollender, Pierre‐Yves Bard, Cécile Cornou, Angkeara Svay, Nikos Theodoulidis; Wavefield Characteristics and Spatial Incoherency: A Comparative Study from Argostoli Rock‐ and Soil‐Site Dense Seismic Arrays. Bulletin of the Seismological Society of America 2018;; 108 (5A): 2839–2853. doi: https://doi.org/10.1785/0120180025 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 Recordings from two dense arrays deployed at Argostoli, Cephalonia Island, Greece, are analyzed with three objectives: (1) exploring to what extent the diffracted surface waves influence the seismic wavefield at a rock site, (2) investigating the loss of coherency of ground motions, and (3) comparing the results for two nearby sites with different soil conditions. The two dense arrays under consideration consist of 21 velocimeters encompassing a central station in four concentric circles with diameters 10–180 m at the soft‐soil site and 20–360 m at the rock site. The datasets include 40 or more events with relatively homogeneous distributions in epicentral distances (10–200 km), magnitudes (2–5), and back azimuths. The wavefields are analyzed using the MUSIQUE algorithm: back azimuth and slowness of dominant incoming waves are extracted, and Love and Rayleigh waves are identified. Average lagged coherency estimates are provided for interstation distances 10–20, 20–30, 30–40, and 80–90 m. Coherency is observed to be generally larger on the rock site compared with the soft‐soil site, especially at frequencies below 5 Hz. At the soil site, lower coherency is observed for pairs along the valley‐perpendicular direction while no such directional dependence is observed at the rock. Although about 40%–60% of the seismogram energy at the soft‐soil site could be associated with diffracted surface waves (Love and Rayleigh) propagating along the valley‐perpendicular direction, only about 20% of energy at the rock site could be characterized as diffracted surface waves. Comparison with the widely quoted parametric models reveals little correlation with the observed decay of coherency at both sites. These significant differences between rock and soft‐soil array results indicate that the spatial incoherency is largely site dependent and is likely to be closely related to the formation of locally generated wavefield. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.