Spatial variation of Lg-wave attenuation in the Iberian Peninsula

Autor: M. José Jurado, Raquel Noriega, Arantza Ugalde, Antonio Villaseñor
Přispěvatelé: Ministerio de Ciencia e Innovación (España)
Rok vydání: 2014
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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Popis: Lateral variations of crustal seismic attenuation across the Iberian Peninsula were estimated by means of an inversion technique applied to 1Hz Lg Q (Q0) measurements obtained using the two-station method. Seismic data for this study consisted of 59 events with magnitudes 3¿ mb Lg ¿5:4, focal depths less than 30 km, and epicentral distances from 100 to 1000 km ,which were recorded by 343 seismic stations between January 2008 and October 2013. Lg-wave propagation was found to be inefficient or blocked for most of the paths crossing the Mediterranean Sea, the western Alborán Sea, and the Strait of Gibraltar. Spectral ratios collected over 2480 high-quality interstation paths were used to determine Lg Q0 and its frequency dependence (¿). Lg Q0 estimates range from ~75 to ~800. The lateral variations of Lg Q0 correlate well with the major tectonic features of the region and heatflow measurements. The lowest values are found in the Pyrenean range and in eastern and southern Iberia, whereas high Lg Q0 values (i.e.,lower attenuation) characterize the more stable western part of the Iberian Peninsula. The obtained results are also in agreement with previous studies in the area.
R. Noriegawas funded by the Spanish government through the Formación de Personal Investigador (FPI) Ph.D. Grant (BES-2011-044291). A. Ugalde was funded by REPSOL CO-DOS project. This is a contribution of Team Consolider-Ingenio 2010 TOPO-IBERIA (CSD2006-00041) and the MICINN Project CGL2010-21568.
Databáze: OpenAIRE