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Project Slope architecture and evolution of sedimentary regimes
R. Henrich, T. Schwenk, T. Hanebuth, K. Huhn, S. Kasten, M. Kölling, A. Kopf, V. Spieß, T. von Dobeneck
The scientific focus of this project is the understanding of sediment transport processes on ocean margins with special emphasis on the interaction of down-slope and along-slope processes. Mass wasting phenomena at continental margins have become a hot topic in recent time because of their coastal geo-hazard potential. In addition, deposition (and erosion) related to along-slope transport processes documents the impact of bottom currents in time and space. Whereas some continental margin types such as high latitude glaciated margins, glacially influenced mid latitude margins as well as tropical margins have been intensely studied, our main study area during the past years, the NW African margin, stretch¬ing from the hyperarid Sahara to the humid Senegal region, has filled a gap as a key location for atmospheric sediment input (i.e. Saharan dust) linked to high biogenic (sediment) production induced by costal upwelling.
The focal study site for this project is the Argentina/Uruguay margin (Fig. 1), which forms a very contrasting setting that is characterized (1) by the huge discharge of the Rio de la Plata draining an extensive hinterland, (2) by the Malvinas-Brazil Current confluence, a prominent element in global surface water circulation and (3) by forming a key location in the intermediate and deep water global conveyor belt, with both the latter having a major impact on lateral sediment transport. This study area has been investigated during RV Meteor Cruise M78/3 in May-July 2009 by means of hydroacoustic and seismic mapping as well as geological sampling with conventional tools and MeBo coring. First analysis of the data has demonstrated that the Uruguayan and northern Argentinean continental margin is controlled by the strong interaction of gravitational downslope and alongslope sediment transport processes (Krastel et al., 2011). Recent research activities concentrate on the interdisciplinary studies of submarine landslides and their potential trigger mechanism (Henkel et al., 2011 a,b), the build-up of contourites with respect to changes in the regional current regime and the sedimentation in the Mar del Plata Canyon in the interplay between gravity‐driven and current‐driven transport mechanism in relation to paleoclimate and/or paleoceanographic variations.
As second main study area the Galician Margin (NW-Spain) was visited during cruise M84/4 in May 2011 (Fig. 2). Seismic and hydroacoustic survey were carried out, and geological sampling were done to study sediment transport from shallow to deep waters and current controlled sedimentation, both with respect to the complex tectonic features on this margin.
The scientific focus of this project is the understanding of sediment transport processes on ocean margins with special emphasis on the interaction of down-slope and along-slope processes. Mass wasting phenomena at continental margins have become a hot topic in recent time because of their coastal geo-hazard potential. In addition, deposition (and erosion) related to along-slope transport processes documents the impact of bottom currents in time and space. Whereas some continental margin types such as high latitude glaciated margins, glacially influenced mid latitude margins as well as tropical margins have been intensely studied, our main study area during the past years, the NW African margin, stretch¬ing from the hyperarid Sahara to the humid Senegal region, has filled a gap as a key location for atmospheric sediment input (i.e. Saharan dust) linked to high biogenic (sediment) production induced by costal upwelling.
The focal study site for this project is the Argentina/Uruguay margin (Fig. 1), which forms a very contrasting setting that is characterized (1) by the huge discharge of the Rio de la Plata draining an extensive hinterland, (2) by the Malvinas-Brazil Current confluence, a prominent element in global surface water circulation and (3) by forming a key location in the intermediate and deep water global conveyor belt, with both the latter having a major impact on lateral sediment transport. This study area has been investigated during RV Meteor Cruise M78/3 in May-July 2009 by means of hydroacoustic and seismic mapping as well as geological sampling with conventional tools and MeBo coring. First analysis of the data has demonstrated that the Uruguayan and northern Argentinean continental margin is controlled by the strong interaction of gravitational downslope and alongslope sediment transport processes (Krastel et al., 2011). Recent research activities concentrate on the interdisciplinary studies of submarine landslides and their potential trigger mechanism (Henkel et al., 2011 a,b), the build-up of contourites with respect to changes in the regional current regime and the sedimentation in the Mar del Plata Canyon in the interplay between gravity‐driven and current‐driven transport mechanism in relation to paleoclimate and/or paleoceanographic variations.
As second main study area the Galician Margin (NW-Spain) was visited during cruise M84/4 in May 2011 (Fig. 2). Seismic and hydroacoustic survey were carried out, and geological sampling were done to study sediment transport from shallow to deep waters and current controlled sedimentation, both with respect to the complex tectonic features on this margin.
Figure 1: Working area offshore Argentina/Uruguay and bathymetric map of the Mar del Plata Canyon.
Figure 2: 3-D perspective view on the Galician Margin (bathymetric data from Cruise M84/4).