Abstract
We report that asperities with the highest coseismic slip in the 2014 MW6.9 North Aegean earthquake persisted through the interseismic, coseismic and immediate post-seismic periods. We use GPS and seismic data to obtain the source model of the 2014 earthquake, which is located on the western extension of the North Anatolian Fault (NAF). The earthquake ruptured a bilateral, 90 km strike-slip fault with three slip patches: one asperity located west of the hypocentre and two to the east with a rupture duration of 40 s. Relocated pre-earthquake seismicity and aftershocks show that zones with significant coseismic slip were relatively quiet during both the 7 yr of interseismic and the 3-month aftershock periods, while the surrounding regions generated significant seismicity during both the interseismic and post-seismic periods. We interpret the unusually long fault length and source duration, and distribution of preand post-main-shock seismicity as evidence for a rupture of asperities that persisted through strain accumulation and coseismic strain release in a partially coupled fault zone. We further suggest that the association of seismicity with fault creep may characterize the adjacent Izmit, Marmara Sea and Saros segments of the NAF. Similar behaviour has been reported for sections of the San Andreas Fault, and some large subduction zones, suggesting that the association of seismicity with creeping fault segments and rapid relocking of asperities may characterize many large earthquake faults.
Original language | English |
---|---|
Pages (from-to) | 1113-1120 |
Number of pages | 8 |
Journal | Geophysical Journal International |
Volume | 213 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 May 2018 |
Bibliographical note
Publisher Copyright:© The Author(s) 2018. Published by Oxford University Press on behalf of The Royal Astronomical Society.
Funding
Pre-earthquake GPS surveys were supported by TÜB˙TAK YD-ABAG (Project no: 103Y033) and ˙TÜ BAP (Project no: 30548) projects. MIT participation was supported in part by NSF Grant EAR-1622560. HK was supported by USIAS SEISNAF grant during his contribution to this work. We would like to thank two reviewers, Piero Poli and Romain Jolivet, for helpful comments on our original submission. We are grateful to Michael Floyd (MIT) for discussions on data processing. The authors would like to thank the General Directory of Land Registry and Cadaster (TKGM), the General Command of Mapping (HGK) and TUBITAK MRC Earth and Marine Sciences Institute for giving access to their GNSS data. All seismic data were downloaded from IRIS Data Services.
Funders | Funder number |
---|---|
USIAS SEISNAF | |
National Science Foundation | 1622560 |
Massachusetts Institute of Technology | |
British Association for Psychopharmacology | 30548 |
National Science Foundation | EAR-1622560 |
Keywords
- Earthquake source observations
- Seismic cycle
- Seismicity and tectonics