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| Titel |
Where giant earthquakes may come |
| VerfasserIn |
Warner Marzocchi, Laura Sandri, Francesca Funiciello, Arnauld Heuret |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250149801
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| Publikation (Nr.) |
 EGU/EGU2017-14189.pdf |
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| Zusammenfassung |
| Giant earthquakes (MW ≥ 8.5) usually occur on the boundary between subducting
and overriding plates of converging margins, but it is not yet clear which (if any)
subduction zones are more prone to produce such a kind of catastrophic events.
Here we analyze the frequency-magnitude distribution of the interplate seismicity
occurred in the time period 1976-2007 at subduction zones. We find that the b-value of
interplate earthquakes is significantly different among the subduction zones. Then, we
calculate the propensity (defined as the average annual rate) of giant interplate
events for about half of the subduction zones (those exhibiting a sufficient number of
interplate earthquakes to carry out the analysis). We find that out-of-sample giant
earthquakes (before 1976 and after 2007) have occurred preferentially in high propensity
areas.
These results show that subduction zones may have different capabilities to produce giant
earthquakes. Besides the importance for seismic hazard assessment and risk mitigation, our
results seem to indicate that a higher seismicity rate does not necessarily imply a higher
likelihood to generate giant earthquakes. Conversely, our results suggest that also subduction
zones with small seismicity rates can have a large propensity to host future giant
earthquakes. Finally, it seems that the way in which the stress is released at a subduction
interface does not change significantly after the occurrence of interplate events. |
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