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| Titel |
Scaling relationship for source parameters of the seismicity of the Corinth Rift (Greece) |
| VerfasserIn |
Emanuela Matrullo, Claudio Satriano, Hélène Lyon-Caen, Pascal Bernard, Anne Deschamps, Panayotis Papadimitriou, Efthimios Sokos, Vladimir Plicka |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250078985
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| Zusammenfassung |
| The improvements in high-density, high-dynamics and broadband seismic observation make
it possible to investigate the proprieties of microearthquake source parameters at very small
scales, in order to better understand the earthquake process similarity over a broad magnitude
range. The issue of earthquake source scaling continues to draw considerable debate
within the seismological community: both supporting and refuting that systematic
differences between the source processes of small and large earthquakes may exist. It
motivates the study of how source parameters, such as seismic moment, corner
frequency, radiated seismic energy, and apparent stress, scale over a wide range of
magnitudes.
On the other hand the estimation of the heterogeneous distribution of seismic
attenuation from the dispersion of amplitude with frequency is important for the
characterization of rock and fluid properties, e.g., saturation, porosity, permeability,
and viscosity, because attenuation is more sensitive than velocity to some of these
properties.
To address these questions, we analyze the seismicity recorded from 2000 to 2011 by the
Corinth Rift Laboratory european project (http:/crlab.eu) covering the western part of the
Corinth Rift (Greece). The network was composed in 2000 of 12 recording stations, with
short period three component seismometers. Over the years 6 broadband stations have been
added. The Corinth Rift (Western Greece) is one of the most seismic active area in Europe
with several instrumental and historical earthquakes (at least 5 earthquakes with magnitude
larger than 5.8 in the last 35 years), several seismic swarms and significant background
seismicity.
The database consists in about 100,000 events with prevalent normal faulting focal
mechanism and covers five orders of magnitude of seismic moment M0 (10^10 – 10^15
Nm).
We investigate scaling relationships of the source parameters from S-wave signals.
We use a frequency domain parametric approach to estimate seismic moment, corner
frequency and the high-frequency spectral fall-off parameter from earthquake S-wave
displacement spectra. We assume a Brune-type (1970) source, with an inverse omega-square
spectral decay. The data set enables to investigate the scaling of source size and stress drops
as a function of the seismic moment in a wide magnitude range in a dominant extensional
tectonic environment.
A by-product of our study is a Ml vs Mw relationship, which is inferred for events in the
whole analyzed magnitude range (0 |
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