The Great 1822 Aleppo Earthquake: New historical sources and strong ground motion simulation

Abstract

The devastating 1822 earthquake is one of the relatively recent events that struck northwestern Syria and the nearby areas of central-southern Turkey, at the junction of the Dead Sea fault system with the Eastern Anatolian fault system. This earthquake is re-examined, in this work, based on new original contemporary and near contemporary sources of information not cited in previous litera- ture. Analysis of these sources reveals the following: (1) more detailed descriptions of the earthquake effects are provided for cities of Aleppo, Antakia and Latakia, and the identification of six new loca- tions affected; (2) assessment of relevant earthquake parameters such as the epicenter, surface-wave, moment magnitudes and seismic intensity; (3) documentation of evidences of a seismic sea wave that occurred between the Cypriot and the Syrian coasts and (4) identification of the Saint Simeon fault, located to west of Aleppo, as the probable causative fault. Furthermore, the ground motion gener- ated by the 1822 earthquake has been simulated using the extended stochastic simulation method. Acceleration time series and damped pseudo acceleration spectra were generated for Aleppo Citadel, where the peak ground acceleration, due to the earthquake, has been estimated at 0.4 g. The results will contribute to updating the seismic hazard setting in the northwestern Syria and central-southern Turkey.

Identification of Source Faults of Large Earthquakes in the Turkey‐Syria Border Region Between 1000 CE and the Present, and Their Relevance for the 2023 Mw 7.8 Pazarcık Earthquake

“…Different authors have placed the 1822 event either on the Amanos fault (e.g., Seyrek et al., 2007), the Yesemek fault (e.g., Ambraseys & Melville, 1995; Duman & Emre, 2013), or the St. Simeon fault (e.g., Darawcheh et al., 2022; Karakhanian et al., 2008). Even not considering the likely presence of this earthquake in the trenches of Altunel et al.…”

“…Different authors have placed the 1822 event either on the Amanos fault (e.g., Seyrek et al, 2007), the Yesemek fault (e.g., Ambraseys & Melville, 1995;Duman & Emre, 2013), or the St. Simeon fault (e.g., Darawcheh et al, 2022;Karakhanian et al, 2008). Even not considering the likely presence of this earthquake in the trenches of Altunel et al (2009) and Akyüz et al (2006) along the Orontes river valley, the Amanos fault is the least likely option: (a) the damage pattern from the 1822 M w 7.5 earthquake is shifted east and south compared to the damage pattern of the 2023 M w 7.8 earthquake (which definitely ruptured the Amanos segment, see Figure 2b), (b) several foreshocks (the strongest preceding the mainshock by 30 min) occurred in the region between Antakya, Latakia and Aleppo (Ambraseys, 1989(Ambraseys, , 2009, suggesting that the main shock may have been triggered by the rupture of one of the many north-south faults between the northern Ghab basin and the Amik basin, and (c) the epicenter estimated for the 1822 event by both Ambraseys (1989) and Sbeinati et al (2005) is located ∼20 km east of the Yesemek fault trace, albeit 60 km apart in latitude in either work (the location shift is also likely due to the exclusion of the Turkish area around Gaziantep from the 2005 catalog).…”

“…This is consistent with the position and orientation of both the Yesemek fault and the northern segment of the St. Simeon fault. Darawcheh et al (2022) explicitly argue for the 1822 event to have originated on the St. Simeon fault. These authors, however, identify as source fault what they call the "middle segment" of the St. Simeon fault (actually, it is the southern segment, see Figure 4): this is a mere 26 km long and a series of very short en-echelon segments (possibly a shear zone without a throughgoing fault near the surface), that is, too short to produce an earthquake of this magnitude.…”