A New Fault Slip Mode Unveiled in the Regional Dynamic Triggering of the 2023 Turkey Kahramanmaraş Earthquake Sequence
Heng Luo, Yijian Zhou, Zeyan Zhao, Mehmet Köküm, Teng Wang, Han Yue, Zexin Wang, Nan Hu, Abhijit Ghosh, Xiaodong Song, Roland Bürgmann
Abstract
Abstract Faults can slip at vastly different rates, generating both high‐stress‐drop regular earthquakes and low‐stress‐drop slow slip events (SSEs). Here, we document a transitional mode of high‐stress‐drop but “silent” slip with two M w 5 events that were triggered by the 2023 Turkey Kahramanmaraş earthquake sequence. Specifically, we identify eight fault slip events from radar interferometry, none of which are reported in seismic catalogs. Except for four typical aseismic creep events, two events represent earthquakes whose waveforms were obscured within the coda waves of the mainshocks. Notably, we find two silent events that did not radiate discernible high‐frequency seismic energy nor produce local aftershocks but did exhibit high stress drops of 4–6 MPa, similar to regular earthquakes. These two “silent” events likely represent a new fault slip mode positioned between regular earthquakes and SSEs. The identification of these diverse shallow slip events, which are missed in seismic catalogs, calls for reevaluation of faulting mechanisms, the nature of static/dynamic triggering effects, and seismic hazard assessments.