Dynamic triggering along the Dead Sea transform uncovers tremor source physics

Abstract

Tremor signals are weak and emergent, and the physics governing their generation is not well understood. Here, I report on tremor occurring along the Dead Sea Transform (DST), and a microearthquake on the Carmel-Fari'a Fault (CFF), both dynamically triggered by the 2023 Mw7.6 Kahramanmaraş earthquake. The triggered events location coincides with maxima of long-period velocity gradients, concentrated in the CFF-DST intersection and near a CFF fault-jump. Relative to other remotely triggered tremors, the DST tremor is strong and deficient in high-frequency seismic energy. Furthermore, analysis of several triggered tremor episodes suggests that tremors spectral fall-off rates are not universal. I discuss the seismological attributes that may give rise to these observations in the context of two models. In the first, tremor is produced due to inertial vibrations of a frictionally-controlled oscillator, and in the second it is produced by a swarm of Low-Frequency Earthquakes.

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

“…In search of local earthquakes within the surface and coda waves of the Kahramanmaraş mainshocks, we inspected all the ISN recorded strong‐motion and broad‐band seismograms of the M w 7.8 and M w 7.6 earthquakes. Evidence of tremor, found in the Jordan Valley, and microearthquakes, found in the Jezre'el Valley, both instantaneously triggered by the M w 7.6, are discussed in detail by (Inbal, 2023). Here, we focus on non‐triggering and triggering in the DS area.…”