A Stochastic View of the 2020 ElazığM_w6.8 Earthquake (Turkey)

Abstract

Until the Mw 6.8 Elazığ earthquake ruptured the central portion of the East Anatolian Fault (EAF, Turkey) on January 24, 2020, the region had only experienced moderate magnitude (Mw < 6.2) earthquakes over the last century. We use geodetic data to constrain a model of subsurface fault slip. We adopt an unregularized Bayesian sampling approach relying solely on physically justifiable prior information and account for uncertainties in both the assumed elastic structure and fault geometry. The rupture of the Elazığ earthquake was mostly unilateral, with two primary disconnected regions of slip. This rupture pattern may be controlled by structural complexity. Both the Elazığ and 2010 Mw 6.1 Kovancılar events ruptured portions of the central EAF that are believed to be coupled during interseismic periods, and the Palu segment is the last portion of the EAF showing a large fault slip deficit which has not yet ruptured in the last 145 years.

Multi‐Scale Rupture Growth With Alternating Directions in a Complex Fault Network During the 2023 South‐Eastern Türkiye and Syria Earthquake Doublet

“…Although the EAF has been less seismically active than that around the NAF since instrumental‐based catalogs started (e.g., Ambraseys, 1989), the EAF has hosted magnitude M 7+ earthquakes in the past, for example, an M 7.1 1893 in Çelikhan, an M 7.4 1513 in Pazarcık, and an M 7.5 in 1822 to the east of Hassa (Ambraseys, 1989; Ambraseys & Jackson, 1998; Duman & Emre, 2013). Most recently, in 2020, a moment magnitude M W 6.8 Doğanyol–Sivrice earthquake broke the region east of the 1893 M 7.1 earthquake (Melgar et al., 2020; Pousse‐Beltran et al., 2020; Ragon et al., 2021; Taymaz et al., 2021), located to the north‐east of the 2023 earthquakes focused on in this study. The EAF is recognized to have multiple geometrically segmented faults and a series of bends, step‐overs, and sub‐parallel faults, leading to complex fault networks (Figure 1) (e.g., Duman & Emre, 2013).…”

Velocity and Temperature Dependence of Steady‐State Friction of Natural Gouge Controlled by Competing Healing Mechanisms

“…The complex frictional behavior of natural gouge may explain the non‐stationary creeping behavior observed in other faults, such as the Laohushan segment of the Haiyuan fault (Jolivet et al., 2012, 2013; Li et al., 2021), and the Pütürge and Palu segments of the East Anatolian Fault (Bletery et al., 2020; Cakir et al., 2023; Ragon et al., 2021). The temperature dependence of gouge friction also implies variations in fault behavior with depth, including the prevalence of a shallow slip deficit during large earthquakes (Barbot et al., 2023; Fialko et al., 2005; Qiu et al., 2020) and variations of interseismic coupling as a function of depth (e.g., Jolivet et al., 2015).…”