Non-Triggering and Then Triggering of a Repeating Aftershock Sequence in the Dead Sea by the 2023 Kahramanmaraş Earthquake Pair: Implications for the Physics of Remote Delayed Aftershocks

Most aftershocks occur in areas experiencing large co-seismic stress changes, yet some occur long after the mainshock in remote lightly stressed regions. The triggering mechanism of these remote delayed aftershocks is not well understood. Here, we study aftershocks occurring in the Dead Sea (DS) area following the 2023 M_w7.8 and M_w7.6 Kahramanmaraş earthquakes. Most aftershocks cluster along previously quiescent structures off- the main DS fault strand. Visual inspection disclosed three aftershocks instantaneously triggered by the M_w7.6 in the northern DS basin, and match-filtering revealed a delayed aftershock. Waveform similarity and temporal clustering suggest the northern DS aftershocks re-rupture a stick-slip patch loaded by surrounding creep. Velocity-gradient seismograms show the M_w7.6 exerted larger transient stresses than the M_w7.8, which may explain triggering by the M_w7.6, but not by the M_w7.8. This account of instantaneously triggered repeaters underscores the role of interactions between aseismic and seismic slip in remote triggering.