Earthquake and Slip-rate History of the Middle Branch of the Northern Anatolian Fault, Türkiye
Description:
We present results from paleoseismic trenching and geomorphic mapping on the middle branch of the Northern Anatolian Fault (MNAF) in Türkiye. A recent geodetic study indicates lower slip rates (~2.5 mm/yr) on the MNAF relative to the more seismically active northern branch. However, historical, archeological, and paleoseismic studies show the MNAF has hosted several damaging earthquakes in the last two millennia and indicate right-lateral slip rates of up to ~5.3 mm/yr. Whether geodesy represents a present-day reduction in slip rates along this branch of the Northern Anatolian fault and/or earthquake clustering is not clear. We conducted geomorphic mapping and paleoseismic trenching along the understudied easternmost section of the MNAF to determine slip rates over different temporal scales and to understand its earthquake history. Our paleoseismic trench suggests up to four surface rupturing earthquakes on this section of the MNAF and our geomorphic mapping indicates variable offsets of river terraces and channels. By dating the paleo-earthquakes and the different offset geomorphic features, we will determine slip rates over variable temporal scales and an earthquake record for this segment of the MNAF. These data will help confirm if there is an observed reduction in slip rates at present day. Conversely, we may see that the reduction in slip rate is apparent and due to earthquake clustering. This result could indicate that longer term geologic slip rates that average out earthquake clusters are more appropriate inputs for time-independent seismic hazard models of MNAF.
Session: Temporally Variable Records of Earthquake Behavior and Considerations for Seismic Hazard Analyse [Poster]
Type: Poster
Date: 4/17/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Nicolas
Student Presenter: No
Invited Presentation:
Poster Number: 32
Authors
Nicolas Harrichhausen Presenting Author Corresponding Author nharrichhausen@alaska.edu University of Alaska Anchorage |
Tunahan Aykut tunahan_aykut_official@hotmail.com Istanbul Technical University |
Julia de Sigoyer julia.de-sigoyer@univ-grenoble-alpes.fr National Center for Scientific Research, French National Research Institute for Sustainable Development, Université Grenoble Alpes, Université Savoie Mont Blanc, Université Gustave Eiffel, Institute of Earth Sciences |
Yann Klinger klinger@ipgp.jussieu.fr Paris Cité University, Paris Institute of Earth Physics, French National Centre for Scientific Research |
Cengiz Yıldırım cyildirim@itu.edu.tr Istanbul Technical University |
Çağdaş Mert Baka cagdasmertbaka1@gmail.com Istanbul Technical University |
Adélaïde Allemand allemand@ipgp.fr Paris Cité University, Paris Institute of Earth Physics, French National Centre for Scientific Research |
Yao Wenqian yao@ipgp.fr Paris Cité University, Paris Institute of Earth Physics, French National Centre for Scientific Research |
Melike Karakaş karakas17@itu.edu.tr Istanbul Technical University |
Earthquake and Slip-rate History of the Middle Branch of the Northern Anatolian Fault, Türkiye
Session
Temporally Variable Records of Earthquake Behavior and Considerations for Seismic Hazard Analyses