A Possible Submarine Landslide and Associated Tsunami at the Northwest Nile Delta, Mediterranean Sea

Abstract

A hypothetical landslide tsunami at the Nile Delta in the Eastern Mediterranean Sea is modeled in order to study hazards it would pose to the region. The methodology used is based on numerical simulation of the generation and propagation of a realistic landslide scenario. The volume of the landslide source is 41 km3, located offshore northern Egypt. The maximum simulated wave heights along the northern, southern, and eastern coasts in the region are in the range of 1–12, 1–6.5, and 0.5–3 m, respectively. The maximum tsunami current velocity along the coasts reaches ~ 2–5 m s–1. Simulations show that bathymetric features in the region and the coastal morphology focus the maximum tsunami waves into some specific paths along which the largest tsunami runup heights occur. The semi-enclosed nature of the eastern Mediterranean causes wave reflections, which result in several wave trains arriving at every coastal site. In some coastal sites, the largest simulated wave belongs to the second wave train, indicating that wave reflection is responsible for this delayed large wave. Based on the results, deployment of a network of deepwater pressure gauges may help in detection and early warning of possible landslide-generated tsunamis in the Eastern Mediterranean.

Keywords

• submarine landslide
• undersea natural hazard
• geohazard
• landslide tsunami
• Nile Delta
• tsunami simulation