No significant steady state surface creep along the North Anatolian Fault offshore Istanbul: Results of 6months of seafloor acoustic ranging


Sakic P., PIETE H., BALLU V., ROYER J. -. , KOPP H., LANGE D., ...More

GEOPHYSICAL RESEARCH LETTERS, vol.43, no.13, pp.6817-6825, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 13
  • Publication Date: 2016
  • Doi Number: 10.1002/2016gl069600
  • Journal Name: GEOPHYSICAL RESEARCH LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.6817-6825
  • Istanbul Technical University Affiliated: Yes

Abstract

The submarine Istanbul-Silivri fault segment, within 15km of Istanbul, is the only portion of the North Anatolian Fault that has not ruptured in the last 250years. We report first results of a seafloor acoustic ranging experiment to quantify current horizontal deformation along this segment and assess whether the segment is creeping aseismically or accumulating stress to be released in a future event. Ten transponders were installed to monitor length variations along 15 baselines. A joint least squares inversion for across-fault baseline changes, accounting for sound speed drift at each transponder, precludes fault displacement rates larger than a few millimeters per year during the 6month observation period. Forward modeling shows that the data better fit a locked state or a very moderate surface creepless than 6mm/yr compared to a far-field slip rate of over 20mm/yrsuggesting that the fault segment is currently accumulating stress.