Onset of aseismic creep on major strike-slip faults


Çakır Z., Ergintav S., Ozener H., DOĞAN U. , Akoglu A. M. , Meghraoui M., ...More

GEOLOGY, vol.40, no.12, pp.1115-1118, 2012 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 40 Issue: 12
  • Publication Date: 2012
  • Doi Number: 10.1130/g33522.1
  • Title of Journal : GEOLOGY
  • Page Numbers: pp.1115-1118

Abstract

Time series analysis of spaceborne synthetic aperture radar (SAR) data, GPS measurements, and field observations reveal that the central section of the Izmit (Turkey) fault that slipped with a supershear rupture velocity in the A. D. 1999, M-w 7.4, Izmit earthquake began creeping aseismically following the earthquake. Rapid initial postseismic afterslip decayed logarithmically with time and appears to have reached a steady rate comparable to the pre-earthquake full fault-crossing rate, suggesting that it may continue for decades and possibly until late in the earthquake cycle. If confirmed by future monitoring, these observations identify postseismic afterslip as a mechanism for initiating creep behavior along strike-slip faults. Long-term afterslip and/or creep has significant implications for earthquake cycle models, recurrence intervals of large earthquakes, and accordingly, seismic hazard estimation along mature strike-slip faults, in particular for Istanbul which is believed to lie adjacent to a seismic gap along the North Anatolian fault in the Sea of Marmara.