Mass Wasting Along Atlantic Continental Margins: A Comparison Between NW-Africa and the de la Plata River Region (Northern Argentina and Uruguay)
The passive continental margins of the Atlantic Ocean are characterized by thick sedimentary successions, which might become unstable resulting in landslides of various sizes. The type of mass-wasting differs between individual margin sections but the reasons for these differences are not well understood. The NW-African continental margin is characterized by several large-scale but infrequent landslides, while the continental margin in the de la Plata River region (northern Argentina and Uruguay) shows widespread small-scale mass transport deposits. These different styles of mass wasting can be explained by different oceanographic and sedimentary settings. The margin off Northwest Africa is characterized by high primary productivity caused by oceanic upwelling as well as locally focused aeolian input resulting in relatively high sedimentation rates. This setting leads to sediment instabilities arising primarily from underconsolidation of deposited sediments and widespread weak layers. In contrast, the modern ocean margin off Uruguay and northern Argentina is characterized by strong contour currents and a high amount of fluvial sediment resulting in widespread contouritic deposits. These contourites are potentially unstable leading to smaller but more frequent landslides.
KeywordsSubmarine landslides Passive margins Atlantic Ocean Acoustic imaging
We thank all scientists and crew who supported data collection during numerous cruises. The authors are thankful to Domenico Ridente and Asrar Talukder for their reviews and constructive comments. Financial support was provided by the Deutsche Forschungsgemeinschaft.
- Benavídez Sosa A (1998) Sismicidad y sismotectónica en Uruguay. Física de la Tierra 10:167–186Google Scholar
- Booth JS, O’Leary DW, Popenoe P et al (1993) U.S. Atlantic continental slope landslides: their distribution, general attributes, and implications. In: Schwab WC, Lee HJ, Twichell DC (eds) Submarine landslides: selected studies in the U.S. Exclusive Economic Zone, U.S. Geological Survey bulletin 2002. U.S. Geological Survey, Denver, pp 14–22Google Scholar
- Georgiopoulou A, Masson DG, Wynn RB et al (2010) The Sahara Slide: initiation and processes from headwall to deposit of a giant submarine slide. Geochem Geophys Geosyst 11(7). doi: 10.1029/2010GC003066
- Harbitz CB, Løvholt F, Pedersen G et al (2006) Mechanisms of tsunami generation by submarine landslides: a short review. Nor J Geol 86:255–264Google Scholar
- Henkel S, Strasser M, Schwenk T et al (2011) An interdisciplinary investigation of a recent submarine mass transport deposit at the continental margin off Uruguay. Geochem Geophys Geosyst 12(Q08009). doi: 10.1029/2011GC003669
- Krastel S, Wynn RB, Hanebuth TJJ et al (2006) Mapping of seabed morphology and shallow sediment structure of the Mauritania continental margin, Northwest Africa: some implications for geohazard potential. Nor J Geol 86:163–176Google Scholar
- Krastel S, Wynn RB, Georgiopoulou A et al (2012) Large scale mass wasting at the NW-African Continental Margin: some general implications for mass wasting at passive continental margins. In: Yamada Y et al (eds) Submarine mass movements and their consequences, Advances in natural and technological hazards research 31. Springer, Dordrecht, pp 189–199CrossRefGoogle Scholar
- Masson DG, Wynn RB, Talling PJ (2010) Large landslides on passive continental margins: processes, hypotheses and outstanding questions. In: Mosher DC et al (eds) Submarine mass movements and their consequences, Advances in natural and technological hazards research 28. Springer, Dordrecht, pp 153–165Google Scholar
- Sarnthein M, Koopmann B (1980) Late Quaternary deep-sea record on northwest African dust supply and wind circulation. Palaeoecol Afr 12:239–253Google Scholar