Mt. Etna is the largest and one of the best-studied volcanoes in Europe. It represents a highly active basaltic volcano on top of the active Apennine thrust belt. The instability of its eastern flank has been described as an important preconditioning factor for the occurrence of submarine mass wasting events. In order to better understand the processes that may cause submarine slope failures, a new dataset including seismic, hydroacoustic and core data was collected during RV Meteor cruise M86/2 from December 2011 to January 2012. Seismic profiles and sediment cores reveal repeated mass transport deposits (MTD), indicating a long history of landslides in the working area. Some of the sampled MTDs and their surrounding strata contain volcaniclastic debris, indicating that slope failures may be controlled by volcanic and non-volcanic processes. Several tephra layers directly cover MTDs, which is regarded as an indicator for the possibility that several flank failures occur immediately before or very early during an eruption.

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.

The Pacific Margin of Costa Rica is an area of intense tectonic deformation and repeated slope instability. Several processes are assumed to affect the long-term stability of the slope. Convergence-related seamount subduction and erosion are the primary reasons for large-scale failures at the lower slope. A second type of smaller slope failures occurs on the upper slope coincident with the landward termination of the regional Bottom Simulating Reflector (BSR). The coincidence of the BSR boundary and the position of slide headwalls might suggest a close genetic relationship. In this paper we present a detailed analysis of the so called “BGR Slide”, a small-type submarine landslide located on the upper slope offshore the Golfo de Nicoya. The 60 m-high headwall is embedded in an area characterized by small canyon structures on the continental slope in water depths where the regional BSR reaches the sea floor. The slide with a volume of ∼0.3 km³ affected an area of ∼8 km². Our acoustic data set suggest faults and migrating fluids playing key roles as preconditioning factors for slope failure, while there is no clear indication for the occurrence of gas hydrates in the headwall region. Furthermore, we assume that an external trigger, e.g., an earthquake, finally initialized the sediment mobilization.

Fjords are important depositional settings and sinks for a variety of geochemical cycles. Their very high resolution records provide the opportunity to relate terrestrial with marine paleo-records. Fjords can preserve morphological evidence of glacial and post-glacial dynamics of the coastal areas of glaciated continental margins. Only few initial studies have focused on fjord environments of NE-Greenland. Here, we present new hydro-acoustic data from inside and off Kong Oscar Fjord. indicating glacial dynamics during the Late and Post-Glacial times. Fast flowing ice filled the fjord and reached at least onto the middle shelf, probably the shelf edge during the LGM. The following retreat of the ice stopped at the mouth of Kong Oscar Fjord. A younger ice advance overrode the grounding line wedge deposited there. This advance may well correlate to the Younger Dryas. It was followed by rapid retreat and/or lift-off of the ice. Post-glaciel sedimentation was characterised by high accumulation of glacio-marine sediments and is affected by recent tectonic activity and submarine mass-wasting in Kong Oscar Fjord.

Proglacial and subglacial glacitectonic sediments and landforms around the margins of the Strait of Magellan, southernmost Chile, record the advance and retreat of outlet glaciers of the Patagonian ice cap during the last glacial cycle. The spatial arrangement of glacitectonic landforms in the area is inferred to have resulted from the advance of ice lobes with cold-based margins and wet-based interiors. As the ice advanced, subglacial basins were excavated beneath the glacier margins and the eroded material was pushed up into thrust moraines, probably because frozen-bed conditions formed a thermal dam against the free drainage of subglacial meltwater. These ice-marginal glacitectonic landforms were then overridden and streamlined into drumlins and flutes as thicker, wet-based ice passed over the area. Evidence for permafrost near sea level in Patagonia during the last glaciation suggests that mean annual temperatures were several degrees lower than indicated by recent modelling studies. The results indicate that future modelling experiments should incorporate more realistic basal boundary conditions, particularly the presence of a weak deforming layer at the glacier bed, to improve climatic reconstructions of southern South America.

Acoustic data reveal giant submarine slides offshore Senegal. The most prominent slide, named Dakar Slide, shows a headwall with a length of at least 100 km in water depths of 2,000-3,100 m. The slide is situated between two canyons, the Dakar Canyon in the north and the Diola Canyon in the south. Seismic data indicate a complex interaction of mass wasting and canyon evolution during the formation of this part of the continental margin. The northern sidewall of the Dakar Slide crosses the distal part of the Dakar Canyon, which was repeatedly destroyed and. filled by slide deposits. The area above the headwall does not show major mass-wasting events though the slope gradient there is significantly steeper. The Dakar Slide is underlain by multiple giant mass transport deposits reaching back to Oligocene times.

The reconstruction of large ice masses in the past is a crucial element for current climate models as correct input and base line parameter as well as for the implementation of associated ice sheet dynamics. For a long time, the ice sheet extent of the Greenland Ice Sheet (GIS) was reconstructed mainly on the basis of terrestrial work. Accordingly, the outer limit of the GIS during the Late Glacial Maximum (LGM) was placed close to the current coastline. Advances in our understanding on the dynamic behaviour of the GIS,especially offshore NE-Greenland, came from hydro-acoustic surveys which indicated a much larger extent of GIS during the LGM. Here, we present hydro-acoustic data acquired with RV “Polarstern” from fjord systems to the shelf edge of NE-Greenland, including the first hydro-acoustic data of Dijmphna and Hekla Sunds. We found morphological evidence for fast-flowing ice filling the fjords, extending onto the shelf as ice stream and reaching the shelf break. Mega-scale glacial lineation, recessional moraines and grounding line wedges document a highly dynamic behaviour of this Westwind Ice Stream of the GIS on NE-Greenland. The ice advance was followed by a rapid retreat to a mid-shelf position where the ice margin repeatedly deposited sets of recessional moraines. A second rapid retreat, probably accompanied by a lift-off of the ice followed and placed the ice margin at the mouth of Dijphna Sund. A last retreat established the modern ice margin in the area. Post-glacial sedimentation was affected by mud diapirism, neo-tectonic activity and submarine mass-wasting inside Dijphna and Hekla Sunds.