RAPID: Geotechnical Engineering and Geo-Sciences Response to the 6 February 2023 Turkiye Earthquake Sequence

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

The 6 February 2023 Türkiye Earthquake Sequence involved large-magnitude, strike-slip earthquakes along plate boundary faults. Similar strike-slip plate boundary faults exist in many other areas globally, including California. While the presence of the faults is known, much remains unknown about the effects of earthquakes on those faults, both in terms of the associated seismic hazards (levels of ground motion) and the impacts on people and infrastructure. As such, it is essential that the earthquake engineering and seismology communities learn from this devastating and seminal event. That learning began with a coordinated, multi-nation and multi-institution reconnaissance program jointly organized between the US and Turkey (Cetin et al. 2023, GEER Association Report 082). This Grant for Rapid Reponse Research (RAPID) project builds upon the reconnaissance work to investigate sites that are of special interest, developing the available data to the point that it can be used to advance seismological and engineering modeling, and thereby influence seismic risk reduction. This RAPID award supports researchers conducting targeted investigations at specific locations in the regions affected by two large earthquakes on 6 February 2023. The investigations include: (1) Documenting surface fault rupture by developing Structure from Motion (SfM) models of the full length of the rupture to supplement in-field evaluations at specific locations. (2) Fault trenching/dating near the southern end of the East Anatolian Fault (ruptured in 2023 event) as it transitions to the Dead Sea Fault (did not rupture) to understand how offsets between fault segments can arrest rupture and the “loading” of non-ruptured faults. (3) Characterizing ground motion station sites close to the ruptured fault using surface wave and seismic cone penetration testing, where such data is currently lacking. (4) Performing limited additional reconnaissance at targeted sites such as port facilities. The broader impact of this work is to inform recovery, inform our understanding of multi-fault rupture sequences with application in parts of the US, and populate databases used to build predictive models for surface fault rupture, ground motions, seismic dam performance, seismic lifelines performance, liquefaction triggering and deformations, and seismic foundation performance among others. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.