Months-long seismicity transients preceding the 2023 MW 7.8 Kahramanmaraş earthquake, Türkiye

Abstract

Short term prediction of earthquake magnitude, time, and location is currently not possible. In some cases, however, documented observations have been retrospectively considered as precursory. Here we present seismicity transients starting approx. 8 months before the 2023 MW 7.8 Kahramanmaraş earthquake on the East Anatolian Fault Zone. Seismicity is composed of isolated spatio-temporal clusters within 65 km of future epicentre, displaying non-Poissonian inter-event time statistics, magnitude correlations and low Gutenberg-Richter b-values. Local comparable seismic transients have not been observed, at least since 2014. Close to epicentre and during the weeks prior to its rupture, only scarce seismic activity was observed. The trends of seismic preparatory attributes for this earthquake follow those previously documented in both laboratory stick-slip tests and numerical models of heterogeneous earthquake rupture affecting multiple fault segments. More comprehensive earthquake monitoring together with long-term seismic records may facilitate recognizing earthquake preparation processes from other regional deformation transients.

Intermittent Criticality Multi‐Scale Processes Leading to Large Slip Events on Rough Laboratory Faults

“…Various large earthquakes were observed to be preceded by precursory deformation and foreshock seismicity on varying scales in space and time, but the observed patterns are diverse and do not always occur (e.g., Kanamori, 1981; Kato & Ben‐Zion, 2021; Kwiatek et al., 2023; Sykes, 2021; Wu et al., 2013). Recent studies of laboratory data showed that the use of AI techniques and features derived from AEs can open up new avenues toward forecasting laboratory earthquakes on smooth faults.…”

“…Faults evolve with progressive loading over geological timescales, displaying a qualitatively comparable evolution of many parameters (e.g., localization, b ‐value) regardless of their structural and mechanical complexity (Ben‐Zion & Sammis, 2003; Tchalenko, 1970). However, it is feasible to observe very different precursory signatures, depending on fault structure (roughness, complexity) and other conditions (Ellsworth & Bulut, 2018; Huang et al., 2020; Kato & Ben‐Zion, 2021; Kwiatek et al., 2023). For rough faults, our study suggests that a combination of physics‐based parameters, reinforced with ML techniques, can indicate when the system is entering a critical stage.…”

“…Fault processes leading to large earthquakes have occasionally been observed to produce foreshock activity and aseismic transients, sometimes lasting months or even years prior to the main shock (Bouchon et al., 2013; Kato et al., 2012; Durand et al., 2020; Kwiatek et al., 2023; Schurr et al., 2014; Meng & Fan, 2021). Seismic and aseismic precursors signifying fault damage evolution and progressive localization toward large dynamic ruptures are not well understood due to limited availability and resolution of seismic data and widely varying structures and properties of fault zones (e.g., Ben‐Zion, 2008, and references therein).…”