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| Titel |
The Mw6.7 October 12, 2013 western Hellenic Arc earthquake and seismotectonic implications for the descending slab |
| VerfasserIn |
Vassilios Karakostas, Eleftheria Papadimitriou, Filippos Vallianatos |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104477
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| Publikation (Nr.) |
 EGU/EGU2015-3897.pdf |
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| Zusammenfassung |
| The 2013 earthquake is the largest that occurred in the last four decades along the western
part of the Hellenic subduction zone, causing light damage in western Crete. Since rupture
dimensions and properties of subduction events are in general more difficult to estimate due
to their position in relation with seismological networks geometry, its occurrence provides an
opportunity to investigate its rupture characteristics as in detail as possible, and consequently
to shed more light in the geometry of the descending slab. The western almost rectilinear part
of the convergent front accommodated the great 365 AD Mw8.3 earthquake, the largest event
ever reported in the Mediterranean region, generating a tsunami that affected almost
its entire eastern part. The oceanic plate of eastern Mediterranean, the front part
of the northward moving African lithospheric plate, is subducting northeasterly
beneath the Aegean microplate, the southern portion of Eurasian lithospheric plate
in this area, at a rate of 4.5 cm/yr, frequently accommodating large destructive
earthquakes with magnitudes M>6.5 along the main thrust zone. Historical and
instrumental information reveals that strong (M>6.0) earthquakes, both shallow and
intermediate ones are frequent in the area, although there is not any reference to any
other such strong event. Plate motion is far above the manifestation of seismicity,
probably due to the fact that the seismic coupling coefficient at this plate boundary
has been estimated at approximately 10% or less. The main shock is associated
with a fault patch onto the coupled part of the overriding and descending plates,
with the compression axis being oriented in the direction of plate convergence.
The first 10–days relocated seismicity shows activation of the upper part of the
descending slab, with most activity being concentrated between 10 and 30 km,
with the main shock being located at the bottom of the activated segment. Cross
sectional views of the relocated seismicity evidenced the extent of the main rupture,
along with the off fault aftershock activity. This later is proved to be immediately
triggered by the downdip stress transfer because of the coseismic slip of the main
shock.
This research has been co–funded by the European Union (European Social Fund) and
Greek national resources under the framework of the “THALES Program: SEISMO FEAR
HELLARC” project of the “Education & Lifelong Learning” Operational Programme. |
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