The 2023 Mw 6.8 Al Haouz, Morocco earthquake: A multi-layer reconnaissance framework for the remote sensing and field assessment of landslides, building and heritage damage, and road access disruption in the High Atlas region

Abstract

On 8 September 2023, a Mw 6.8 earthquake struck Morocco's High Atlas region, causing nearly 3000 fatalities and widespread damage across rural, mountainous settlements dominated by traditional and non-engineered construction, and affecting cultural heritage assets. The event triggered landslides that further increased the isolation of affected communities. This study presents findings from the Earthquake Engineering Field Investigation Team (EEFIT) mission. Different radar and optical remote sensing techniques were used to identify areas most affected by earthquake-induced landslides and building damage, guiding the field investigations. A total of 2671 earthquake-induced landslides were identified; although relatively limited for an event of this magnitude, they significantly impacted road accessibility and emergency response. In parallel, 455 buildings were assessed on site and classified using the EMS–98 scale. Seismic performance was primarily influenced by construction practices and detailing rather than structural typology. Traditional unreinforced masonry buildings exhibited the highest vulnerability, largely due to substandard materials and construction practices, and limited upkeep, which are common in remote villages. Hybrid constructions combining traditional and modern techniques also performed poorly. Confined masonry and reinforced concrete buildings generally performed better, although deficiencies in detailing and irregular configurations were frequently observed. Cultural heritage assets sustained predominantly moderate damage, and stabilisation efforts are ongoing. By combining remote sensing and systematic engineering field observations within a common geospatial framework, the study presents a multi-layer reconnaissance framework for interpreting landslide inventories, building damage, and cultural heritage observations together in data-scarce mountainous regions, while highlighting priorities for future research and practice.