Tsunamigenic potential of a Holocene submarine landslide along the North Anatolian Fault (North Aegean Sea, off Thasos Island): insights from numerical modeling

Abstract

Abstract. The North Anatolian Fault in the northern Aegean Sea triggers frequent earthquakes of magnitude up to M w ∼ 7.This seismicity can be a source of modest tsunamis for the surrounding coastlines with less than 50 cm height according to numerical modelling and analysis of tsunami deposits. However, other tsunami sources may be involved, like submarine landslides. We assess the severity of this potential hazard by performing numerical simulations of tsunami generation and propagation from a Holocene landslide (1.85 km 3 in volume) identified off Thasos island. We use a model coupling the simu-5 lation of the submarine landslide, assimilated to a granular flow, to the propagation of the tsunami wave. The results of these simulations show that a tsunami wave of water height between 1.10 m and 1.65 m reaches the coastline at Alexandroupolis (58.000 inhabitants) one hour after the triggering of the landslide. In the same way, tsunamis waves of water height between 0.80 m and 2.00 m reach the coastline of the Athos peninsula 9 min after the triggering of the landslide. Landslide tsunamis should not be neglected as a potential source of tsunami in the area. Despite numerous earthquakes of M w > 7 and strong 10 detrital input (on the order of 30 cm.ka −1 ), only a few Holocene landslides have been recognized so far, asking the question of the relationships between seismicity and landslide frequency in the area.

Submarine Landslides in the West Continental Slope of the South China Sea and Their Tsunamigenic Potential

“…These studies highlight the potential catastrophic tsunami effect on the densely populated coastal regions (e.g., the southern China) in the SCS (Li et al, 2019). Compared with landslides with giant sizes, landslides with volumes on the order of a few km 3 generally generate shorter wavelengths and its wave amplitudes decay faster, and therefore affecting relatively limited coastal areas (Janin et al, 2019). Nonetheless, when such tsunami events occur in densely populated region, small-scale landslides can also trigger non negligible tsunami disasters.…”

Tsunami potential source in the eastern Sea of Marmara (NW Turkey), along the North Anatolian Fault system

“…Values between 0.02 and 0.06, with 0.01 step intervals, were explored, as reported in Fig. S1, within the typical range of submarine landslide simulations (Janin et al 2019;Wang et al 2019;Gargani 2020). We observe that μ influences the landslide run-out (Fig.…”