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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-21 20:26 |
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Conference: Bucharest University Faculty of Physics 2008 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Detailed seismicity analysis in the Vrancea area and implications for the seismic cycle evolution (POSTER)
Authors:
Rogozea Maria, Mihaela Popa, Mircea Radulian
Affiliation:
National Institute for Earth Physics, 12 Calugareni St., 077125, PO Box MG-2 Magurele, Romania,
Tel.: 0214050664; Fax: 0214050665
E-mail
mrogozea@infp.ro
Keywords:
seismicity, seismic cycle
Abstract:
Seismicity of the Vrancea region shows characteristic clustering features in space, time and energy that are clearly related to specific physical processes in the subcrustal domain. To identify and analyze seismicity patterns and their correlation with the seismotectonics and geodynamics modelling, we relocated the Vrancea intermediate-depth earthquakes occurred from 1982 to 2007, for which high-quality data were available. For the study of the frequency-magnitude distribution and seismic cycle behaviour we use Romanian routine catalogue for a 70-year time interval (6589 events) as well as the historical catalogue and information. In the last 100 years, several seismic cycles can be identified in the Vrancea subcrustal domain. Earth cycle is characterized by a shock larger than 6.5 and a relative lack of earthquakes at intermediate magnitudes (6 to 7), which suggests a percolation-type process for the major shocks. A sort of balance for the seismic energy release between an upper active segment located around 90 km depth and a lower active segment located around 140 km depth seems to control the evolution of the successive cycles (at least for the last 100 years). We investigate the implications of the specific seismicity parameters in the two segments related to background and aftershock earthquake activities on the earthquake process evolution.
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