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| Titel |
Exploring the feasibility of an early warning system in a moderate seismicity context: case study of Pyrenees |
| VerfasserIn |
Samuel Auclair, Xavier Goula, Jose-Antonio Jara, Yolanda Colom, Anne Lemoine, Bastien Colas |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250048636
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| Zusammenfassung |
| The massif of Pyrenees, who results from compressive movement between Iberic and
Eurasian tectonic plates and who marks out the natural border between France and Spain,
presents a moderate seismicity responsible of many destructive earthquakes over history,
which maximum magnitude could probably reach 6.0-6.5. Thus Pyrenees constitute one of
the Spanish and French areas where the seismic hazard is the most important, what have led
to the progressive development of seismological forecasting networks around the massif. In
this context, the SISPyr Interreg project (www.sispyr.eu) has as principal objective to allow
the pooling of Pyrenean seismological data and to improve the massif coverage by the
networks favouring the progressive transition to real-time data transfer technologies. In order
to make profit of advantages offer by real-time seismology, the SISPyr project also
aims at to assess the feasibility of a Pyrenean earthquake early warning system
(EEW).
In a first time, the SISPyr seismic network had been examined in order to assess its
adaptability to early warning purposes. In particular, redundancy issues, network coverage,
data processing and time latency of the existing real-time system have been analysed. The
main conclusion of the previous analysis is that the existing network and system could be the
base of an EEW implementation for Pyrenees.
Then different rapid magnitude determination methodologies have been tested (so called
Ïc, Ïpmax and Pd/Pv methods) in order 1) to check their adaptability to the Pyrenean
context and 2) to establish empirical relationships usable in Pyrenees. To that end, a
waveform catalog had first been constituted, gathering more than 4.000 records
from 195 Pyrenean seismic events. The analysis of these records has allowed us to
bringing to light clear correlations between earthquakes’ reference magnitudes
and four waveforms indicators calculated from first seconds of the P wave on the
vertical component. In order to extend the validity domain of these relationships to
greater magnitudes (no Pyrenean data for Ml-¥5.5 events), our data had then been
successfully confronted to different published relationships established from foreign
data.
Today, the main issue is to determine in which extend these “reference” relationships
could be used for early warning purposes in Pyrenees, for earthquakes associated to high
return periods. This analysis relies firstly on the test of a warning emission process, and
secondly on a potential end-users survey in order to evaluate their wishes in terms of
earthquake early warning. |
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