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| Titel |
Unlocking of the North Anatolian Fault prior to the 2014 M 6.9 North Aegean Earthquake: Evidence from seismological and geodetic observations |
| VerfasserIn |
Fatih Bulut, Haluk Ozener, Asli Dogru, Bahadir Aktug |
| 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 |
250151923
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| Publikation (Nr.) |
 EGU/EGU2017-16693.pdf |
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| Zusammenfassung |
| We integrated long-term microseismicity and near-fault GPS measurements to elaborate on generation process of the 2014 M 6.9 Aegean Earthquake. The mainshock ruptured part of the westernmost segments of the North Anatolian Fault (NAF), Turkey. We observed that the 2014 M 6.9 Aegean earthquakes were preceded by almost a decade-long period of enhanced microearthquake activity representing a front-edge fracturing process preparing the failure. Microseismicity-derived pre-seismic low-slip patches are interpreted to represent locked fault sections rather than a pure a-seismic creep. The nucleation of the mainshock occurred at low-slip patches where the lowest pre-slip has been accommodated along the ruptured fault section. For the time period of 2006-2014, acceleration in microseismicity delays for one year with respect to the increase in GPS-derived tectonic motion. This verifies that the tectonic loading drives the acceleration in microseismicity. The direction of GPS-derived velocity field rotates systematically from ~234° to ~244° clockwise, which tends smoothly to be sub-parallel to the local fault strike. This rotation corresponds to upward migration of locking depth from ~13.0 km to ~8.0 km within a time period of eight years suggesting unlocking of the NAF prior to the 2014 M 6.9 North Aegean Earthquake. |
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