لخّصلي

The 2023 Morocco earthquake sequence started on 8 September 2023 at 11:11 p.m., local time, with a MW 6.8 event, followed by a magnitude 4.9 aftershock 19 min later, striking the western sector of the High Atlas Mountains in Morocco (Figure 1), characterized by low geodetic strain rates (Koulali et al., 2011; Serpelloni et al., 2007).Previous geological studies (e.g., Bernard et al., 2010; Sebrier et al., 2006) have identifies several SW-NE trending compressive and transpressive fault systems, some of which were considered active in this area, often representing structures inherited from the Triassic extensional tectonic phases.According to the Centre Sismologique Euro-Mediterraneen (CSEM), to the Portuguese Institute for Sea and Atmosphere (IPMA) and to the United States Geological Survey (USGS), the earthquake's hypocenter was located at a depth of about 20-25 km with its epicenter in the High Atlas Mountains, 70 km southwest of the city of Marrakesh.The earthquake was felt as far away as Portugal and Algeria.

The 2023 Morocco earthquake sequence started on 8 September 2023 at 11:11  p.m., local time, with a MW 6.8 event, followed by a magnitude 4.9 aftershock 19 min later, striking the western sector of the High Atlas Mountains in Morocco (Figure 1), characterized by low geodetic strain rates (Koulali et al.,  2011; Serpelloni et al., 2007). According to the Centre Sismologique Euro-Méditerranéen (CSEM), to the Portuguese Institute for Sea and Atmosphere (IPMA) and to the United States Geological Survey (USGS), the earthquake's hypocenter was located at a depth of about 20–25 km with its epicenter in the High Atlas Mountains, 70 km southwest of the city of Marrakesh. The earthquake was felt as far away as Portugal and Algeria. According to Morocco's Interior Ministry, at least 2,901 people were killed, mostly in Marrakech and in five provinces near the epicenter, and about 320,000 people were exposed to the earthquake, with the remote villages located in the High Atlas Mountains suffering substantial losses and extensive damage. The following seismic sequence was characterized by numerous aftershocks almost entirely shallower than the mainshock and located either in a cluster SSE of the mainshock (CSEM database), or mainly NNE of the epicenter (IPMA database) within the hanging-wall of the mainshock (bottom inset in Figure 1). Fault plane solutions for the main event exhibit transpressional faulting (U.S. Geological Survey, 2023), consistent with the direction of active shortening of about 1.0 ± 0.6 mm/yr in this sector of the High Atlas belt (Koulali et al., 2011). Previous geological studies (e.g., Bernard et al., 2010; Sebrier et al., 2006) have identifies several SW-NE trending compressive and transpressive fault systems, some of which were considered active in this area, often representing structures inherited from the Triassic extensional tectonic phases. However, the strain partitioning between the different fault systems and the recognition of the actual active fault segments is still not completely clear.