The tsunami induced by the 2003 Zemmouri earthquake (<i>M_W</i>= 6.9, Algeria): modelling and results

Abstract

A strong tsunami with sea disturbances observed along the Algerian coast, but with significant damage mainly in the Balearic Islands (Spain) harbours, affected the western Mediterranean following the 2003 Zemmouri earthquake (M W 6.9, Algeria). An average regional uplift of 0.55 m was measured along the shoreline in the epicentral area. Field observations, main shock and aftershocks characteristics are consistent with thrust along a 55-km-long rupture, trending NE-SW, dipping SE. The seismotectonic parameters indicate a hypocentre 7-8 km deep and a possible fault break between 5 and 15 km offshore. Several tide gauges located in the western Mediterranean Coast indicated an average of 0.4 m of sea-level change with a maximum of 2 m in the Balearic Islands. We generated high-resolution bathymetry grids from the Algerian coasts to the Balearic Islands coasts in order to test different seismic sources (with different fault rupture location, strike and dip) and model the tsunami initiation and propagation.