A complex seismogenic shear zone: The Düzce segment of North Anatolian Fault (Turkey)

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

2

Scientific paper

This work highlights how surface geological data can integrate and complete a fault characterization including its seismogenic depth. We investigated the area struck by the November, 1999, Mw 7.1 earthquake that ruptured the Düzce segment of the North Anatolian Fault Zone (NAFZ) after the August, 1999, Mw 7.4 Izmit earthquake. To explore the persistency or evolution of the active fault setting at the surface, we compared detailed coseismic surface expressions with the long-term morphology and structural architecture of the Düzce zone. We identified a simple 1999 coseismic fault trace (CFT) and an older complex fault system (RFS) involving a wider zone of deformation. Two different parts of the Düzce segment were recognized. A western section presents a staircase trajectory of the coseismic fault trace that reactivated part of the older fault system. An eastern section presents a straight coseismic fault trace that cross-cuts the older and complex fault system. The western Düzce fault segment splays out from the Izmit counterpart of the NAFZ, forming a releasing fault junction. By comparing a model of its coseismic surface deformation field with the long-term morphology, we observed that the present topography of this western section results from the NAFZ activity by repeating coseismic deformations like those in 1999. The mechanical interaction in the release fault junction produces local transtension across the western Düzce fault and justifies its stable complexity. It does not evolve into a straight trace. The surface boundary between the Düzce fault sections also separates at depth two fault sections: one with low slip to the west, and another with a big asperity to the east. Thus, the Izmit/Düzce interaction (1) may produce an unfavorable setting for a build-up of asperities in the western Düzce segment and (2) could delay the propagation of the Izmit rupture along the Düzce segment that nucleates mainshocks only on its eastern section. In other words, the arrangement of the fault junction may permanently control how the two sections of the Düzce fault behave and rupture.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

A complex seismogenic shear zone: The Düzce segment of North Anatolian Fault (Turkey) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A complex seismogenic shear zone: The Düzce segment of North Anatolian Fault (Turkey), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A complex seismogenic shear zone: The Düzce segment of North Anatolian Fault (Turkey) will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1068097

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.