Mass-Transport Deposits on the Algerian Margin (Algiers Area): Morphology, Lithology and Sedimentary Processes

Abstract

Abstract:On 21st May 2003, a damaging earthquake of Mw: 6.9 struck the region of Boumerdès 40 km east of Algiers in northern Algeria. The seismic shocks had devastating effects in the offshore area between the cities of Algiers and Dellys, where numerous cable breaks were observed. The submarine area encompassing the 2003 Boumerdès epicenter (central Algerian margin) was recently investigated using geophysical and sampling tools. It has been observed that small-size slides and mass-transport deposits occur across this area. Thus, a detailed analysis was performed on 25 submarine slides identified in water depth from 500 m to 2700 m, by measuring different morphological parameters (i.e. surface, head-scarp height, slope in the source area and in adjacent areas). Various deposits consisting of matrix supported mud-clast, distorted stratified sediments and sand turbidite beds were observed in gravity cores near and within the most significant-size slide. Based on this work and previous studies it can be presumed that the recurrent seismic activity can be considered as the main triggering factor for failure in the central Algerian margin.

Tectonic Inversion and Geomorphic Evolution of the Algerian Margin Since Messinian Times: Insights From New Onshore/Offshore Analog Modeling Experiments

“…Offshore, the Algerian margin exhibits an unusual morphology compared to the surrounding Mediterranean margins. In central Algeria, the continental slope is characterized by steep scarps of several hundred meters high alternating with perched basins (Dan et al, 2009(Dan et al, , 2010Déverchère et al, 2005;Domzig et al, 2006;Strzerzynski et al, 2010; Figure 2). The continental shelf is very narrow except for a large bathymetric high, called the Khayr al Din Bank or KAD ( Figure 3; Domzig et al, 2006;Yelles et al, 2009).…”

“…Offshore, the Pliocene to present-day deformation is expressed by kilometer-scale wavelength folds located at the foot of the continental slope and in the deep basin (Figures 2 and 3), but also in the upper margin where many slides, active canyons, and gullies mask the cumulated scarps (Dan et al, 2009(Dan et al, , 2010Dan-Unterseh et al, 2011). The area affected by deformations is characterized by a significant seismic activity (Figure 1).…”

Mass‐transport complexes as markers of deep‐water fold‐and‐thrust belt evolution: insights from the southern Magdalena fan, offshore Colombia

“…On tectonically active continental margins, recurrent mass wasting is commonly caused by seabed oversteepening due to structurally induced seabed deformation and/or by seismic activity (e.g. Moore et al ., ; Torelli et al ., ; Goldfinger et al ., ; Frey‐Martinez et al ., , ; Minisini et al ., ; Lamarche et al ., ; Cattaneo et al ., ; Dan et al ., ; Romero‐Otero et al ., ; Geersen et al ., ; Alfaro & Holz, ; Festa et al ., ; Pérez et al ., ). Several studies on active margins have investigated the mechanisms for slope failure and provide detailed descriptions of the deposits resulting from fold degradation (e.g.…”

Routledge Handbook of Ocean Resources and Management

“…Furthermore, a major hazard such as a submarine landslide can damage multiple cables to cause a widespread reduction or even loss of internet and communication traffic. This was the case for earthquake-triggered submarine landslides and turbidity currents off Algeria 2003 (Dan et al, 2003;Cattaneo et al, 2012), southern Taiwan, 2006 (Hsu et al, 2009) and northern Japan, 2011 (studies underway).…”