Capturing Regional Variations of Hard‐Rock κ0 from Coda Analysis
2018; Seismological Society of America; Volume: 108; Issue: 1 Linguagem: Inglês
10.1785/0120170153
ISSN1943-3573
AutoresJessie Mayor, Sanjay Singh Bora, Fabrice Cotton,
Tópico(s)Seismic Waves and Analysis
ResumoResearch Article| January 09, 2018 Capturing Regional Variations of Hard‐Rock κ0 from Coda Analysis Jessie Mayor; Jessie Mayor aGFZ German Research Center for Geosciences, Helmholtzstraße 6/7, 14467 Potsdam, Germany, sanjay.bora@sed.ethz.chbNow at EDF‐Lab Paris‐Saclay, 7 Boulevard Gaspard Monge, 91120 Palaiseau, France. Search for other works by this author on: GSW Google Scholar Sanjay Singh Bora; Sanjay Singh Bora aGFZ German Research Center for Geosciences, Helmholtzstraße 6/7, 14467 Potsdam, Germany, sanjay.bora@sed.ethz.chcNow at Swiss Seismological Service (SED), ETH Zurich, Sonneggstrasse 5, NO H 60, 8092 Zurich, Switzerland. Search for other works by this author on: GSW Google Scholar Fabrice Cotton Fabrice Cotton aGFZ German Research Center for Geosciences, Helmholtzstraße 6/7, 14467 Potsdam, Germany, sanjay.bora@sed.ethz.chdAlso at Institute for Earth and Environmental Sciences, University of Potsdam, 14469 Potsdam, Germany. Search for other works by this author on: GSW Google Scholar Author and Article Information Jessie Mayor aGFZ German Research Center for Geosciences, Helmholtzstraße 6/7, 14467 Potsdam, Germany, sanjay.bora@sed.ethz.chbNow at EDF‐Lab Paris‐Saclay, 7 Boulevard Gaspard Monge, 91120 Palaiseau, France. Sanjay Singh Bora aGFZ German Research Center for Geosciences, Helmholtzstraße 6/7, 14467 Potsdam, Germany, sanjay.bora@sed.ethz.chcNow at Swiss Seismological Service (SED), ETH Zurich, Sonneggstrasse 5, NO H 60, 8092 Zurich, Switzerland. Fabrice Cotton aGFZ German Research Center for Geosciences, Helmholtzstraße 6/7, 14467 Potsdam, Germany, sanjay.bora@sed.ethz.chdAlso at Institute for Earth and Environmental Sciences, University of Potsdam, 14469 Potsdam, Germany. Publisher: Seismological Society of America First Online: 09 Jan 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (1): 399–408. https://doi.org/10.1785/0120170153 Article history First Online: 09 Jan 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jessie Mayor, Sanjay Singh Bora, Fabrice Cotton; Capturing Regional Variations of Hard‐Rock κ0 from Coda Analysis. Bulletin of the Seismological Society of America 2018;; 108 (1): 399–408. doi: https://doi.org/10.1785/0120170153 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 We propose an alternative procedure for the capture of the hard‐rock regional kappa (κ0ref). In our approach, we make use of a potential link between the well‐known κ parameter and the properties of coda waves. In our analysis, we consider near‐distance records of four crustal earthquakes of local magnitude 3.7–4.9 that occurred in four regions of France in different geological contexts: the crystalline axial chain of Pyrenees to the southwest, the large sedimentary basin to the southeast, the Alpine range to the east, and the extensional Rhine graben to the northeast. Each earthquake has been recorded at a pair of nearby soft‐ and hard‐rock station sites. The high‐frequency (16–32 Hz) spectral amplitudes of the coda window (carefully selected on the time series of the accelerograms) confirm an exponential decrease, which we quantify by κAHcoda and call "kappa of coda." It is found that κAHcoda is independent of the soil type but shows significant regional variations. κ measurements (Anderson and Hough, 1984) over the coda window (κAHcoda) and full time series (κAH) show strong correlation at hard‐rock sites. This suggests that κAHcoda can provide a new proxy to estimate the regional hard rock κ0ref (Ktenidou et al., 2015). Theoretical analysis is also presented to relate the regional κAHcoda and coda quality factor Qc, which quantifies the average attenuation properties of the crust (both scattering and absorption). It allows interpreting κAHcoda as the time spent by the waves in the medium, weighted by its attenuation properties. This theoretical analysis also shows that the classical κ measurement should be frequency dependent; this was confirmed by the spectra of the observed records. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
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