Tsunami hazard assessment along the Algerian Coast: A preliminary geodetic mapping approach

 The Algerian coastline, located in a seismically active region of the western Mediterranean, remains vulnerable to understudied but potentially catastrophic tsunami hazards. The 2003 Mw 6.8 Boumerdès earthquake and its associated locally generated tsunami highlighted both the region’s complex tectonic setting and the lack of effective tsunami early-warning capabilities. This preliminary study investigates the potential of integrated geodetic observations to enhance tsunami hazard assessment and early-warning strategies along the Algerian margin. Continuous GNSS data from permanent Algerian and IGS stations are used to detect co-seismic and interseismic vertical and horizontal crustal displacements relevant to tsunami generation. In parallel, Sentinel-1 and ALOS-2 InSAR measurements resolve onshore deformation, coastal subsidence, and potential submarine slope instabilities. Satellite altimetry data from Jason and SARAL missions are analyzed to identify anomalous sea-surface height signals possibly associated with offshore seismic or tectonic processes. These multi-sensor datasets are integrated within a unified geodetic modeling framework and combined with tide-gauge records and numerical tsunami simulations using the Tsunami-HySEA model. Preliminary findings highlight the critical role of geodetic data in early-warning systems and risk mapping, particularly for densely populated coastal cities (Algiers, Oran). This interdisciplinary approach bridges geodesy, seismology, and coastal management, proposing a framework for proactive disaster resilience in North Africa.

Keywords: Tsunami hazard assessment, Algerian Mediterranean coast, GNSS geodetic monitoring, InSAR, Crustal deformation, Early Warning Systems.