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The Drake Passage is an oceanic gateway of about 850 km width located between South America and the Antarctic Peninsula that connects the southeastern Pacific Ocean with the southwestern Atlantic Ocean. It is an important gateway for mantle flow, oceanographic water masses, and migrations of biota. This sector developed within the framework of the geodynamic evolution of the Scotia Arc, including continental fragmentation processes and oceanic crust creation, since the oblique divergence of the South American plate to the north and the Antarctic plate to the south started in the Eocene. As a consequence of its complex tectonic evolution and subsequent submarine processes, as sedimentary infill and erosion mainly controlled by bottom currents and active tectonics, this region shows a varied physiography. We present a detailed map of the bathymetry and geological setting of the Drake Passage that is mainly founded on a new compilation of precise multibeam bathymetric data obtained on 120 cruises between 1992 and 2015, resulting in a new Digital Bathymetric Model with 200 × 200 m cell spacing. The map covers an area of 1,465,000 km2 between parallels 52°S and 63°S and meridians 70°W and 50°W at scale 1:1,600,000 allowing the identification of the main seafloor features. In addition, the map includes useful geological information related to magnetism, seismicity and tectonics. This work constitutes an international cooperative effort and is part of the International Bathymetric Chart of the Southern Ocean project, under the Scientific Committee on Antarctic Research umbrella. © 2018, © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Map.

The Drake Passage is an oceanic gateway of about 850km width located between South America and the Antarctic Peninsula that connects the southeastern Pacific Ocean with the southwestern Atlantic Ocean. It is an important gateway for mantle flow, oceanographic water masses, and migrations of biota. This sector developed within the framework of the geodynamic evolution of the Scotia Arc, including continental fragmentation processes and oceanic crust creation, since the oblique divergence of the South American plate to the north and the Antarctic plate to the south started in the Eocene. As a consequence of its complex tectonic evolution and subsequent submarine processes, as sedimentary infill and erosion mainly controlled by bottom currents and active tectonics, this region shows a varied physiography. We present a detailed map of the bathymetry and geological setting of the Drake Passage that is mainly founded on a new compilation of precise multibeam bathymetric data obtained on 120 cruises between 1992 and 2015, resulting in a new Digital Bathymetric Model with 200x200 m cell spacing. The map covers an area of 1,465,000km2 between parallels 52°S and 63°S and meridians 70°W and 50°W at scale 1:1,600,000 allowing the identification of the main seafloor features. In addition, the map includes useful geological information related to magnetism, seismicity and tectonics. This work constitutes an international cooperative effort and is part of the International Bathymetric Chart of the Southern Ocean project, under the Scientific Committee on Antarctic Research umbrella.

The continental margin of Gondwana preserves a record of long-lived magmatism from the Andean Cordillera to Australia. The crustal blocks of West Antarctica form part of this margin, with Palaeozoic–Mesozoic magmatism particularly well preserved in the Antarctic Peninsula and Marie Byrd Land. Magmatic events on the intervening Thurston Island crustal block are poorly defined, which has hindered accurate correlations along the margin. Six samples are dated here using U-Pb geochronology and cover the geological history on Thurston Island. The basement gneisses from Morgan Inlet have a protolith age of 349±2 Ma and correlate closely with the Devonian–Carboniferous magmatism of Marie Byrd Land and New Zealand. Triassic (240–220 Ma) magmatism is identified at two sites on Thurston Island, with Hf isotopes indicating magma extraction from Mesoproterozoic-age lower crust. Several sites on Thurston Island preserve rhyolitic tuffs that have been dated at 182 Ma and are likely to correlate with the successions in the Antarctic Peninsula, particularly given the pre-break-up position of the Thurston Island crustal block. Silicic volcanism was widespread in Patagonia and the Antarctic Peninsula at ~ 183 Ma forming the extensive Chon Aike Province. The most extensive episode of magmatism along the active margin took place during the mid-Cretaceous. This Cordillera ‘flare-up’ event of the Gondwana margin is also developed on Thurston Island with granitoid magmatism dated in the interval 110–100 Ma.

Trough-mouth fans (TMFs) are large depocentres of glacially influenced sediments formed at the mouths of some glacially carved cross-shelf troughs (Vorren et al. 1989). They develop in front of ice streams grounded at, or near to, the shelf edge, which transported large volumes of glacigenic sediment to the outer shelf and upper slope. The main components of TMFs are prograding outer shelf–upper slope strata which are constructed largely of foresets comprising debris-flow units. They are commonly capped by topsets that may include subglacially deposited tills (Fig. 1f). Mass-wasting deposits, gullies and channels may also occur in conjunction with or within the TMFs.

Submarine gullies are small-scale, confined channels on the order of tens of metres depth that form one of the most common morphological features of high-latitude continental slopes. Gully morphology varies in width, incision depth, length, sinuosity, branching order, shelf-incision, cross-sectional shape and gully spacing, with six distinct gully signatures recognized on high-latitude continental slopes (Gales et al. 2013a, b). Here we analyse the morphology of slope gullies off Halley and Filchner troughs in the southern Weddell Sea (Fig. 1a–f).

Trough-mouth fans (TMFs) are large depocentres of glacially influenced sediments formed at the mouths of some glacially carved cross-shelf troughs (Vorren et al. 1989). They develop in front of ice streams grounded at, or near to, the shelf edge, which transported large volumes of glacigenic sediment to the outer shelf and upper slope. The main components of TMFs are prograding outer shelf–upper slope strata which are constructed largely of foresets comprising debris-flow units. They are commonly capped by topsets that may include subglacially deposited tills (Fig. 1f). Mass-wasting deposits, gullies and channels may also occur in conjunction with or within the TMFs.

Ploughing by deep keels of floating icebergs is a common feature of high-latitude continental margins. Icebergs that have calved from glaciers or ice sheets produce a range of seafloor signatures, including linear to curvilinear grooves, rounded pits and ploughmarks terminating in sediment ridges. The dimensions and patterns of iceberg ploughmarks vary with iceberg size, water depth, local current, tide and wind conditions, seafloor sediment and past glacial history. The outer shelf and upper continental slope of the southern Weddell Sea is extensively ploughed by icebergs, and three different types of iceberg ploughmarks are recognized. The first signature is small grounding pits which occur over a wide area of the upper slope to water depths of c. 720 m (white arrow in Fig. 1a). The grounding pits have a mean depth of 8 m and a mean diameter of 280 m. The pits appear to be distributed randomly, with the highest intensity occurring in water depths of 410–670 m.

The South Sandwich Islands and associated seamounts constitute the volcanic arc of an active subduction system situated in the South Atlantic. We introduce a map of the bathymetry and geological setting of the South Sandwich Islands and the associated East Scotia Ridge back-arc spreading centre that consists of two sides: side 1, a regional overview of the volcanic arc, trench and back-arc, and side 2, detailed maps of the individual islands. Side 1 displays the bathymetry at scale 1:750 000 of the intra-oceanic, largely submarine South Sandwich arc, the back-arc system and other tectonic boundaries of the subduction system. Satellite images of the islands on side 2 are at scales of 1:50 000 and 1:25 000 with contours and main volcanological features indicated. These maps are the fi rst detailed topological and bathymetric maps of the area. The islands are entirely volcanic in origin, and most have been volcanically or fumarolically active in historic times. Many of the islands are ice-covered, and the map forms a baseline for future glaciological changes caused by volcanic activities and climate change. The back-arc spreading centre consists of nine segments, most of which have rift-like morphologies.

The Drake Passage is an oceanic gateway of about 850 km width located between South America and the Antarctic Peninsula that connects the southeastern Pacific and the southwestern Atlantic oceans and is an important gateway for mantle flow, oceanographic water masses, and migrations of biota. This gateway developed within the framework of geological evolution of the Scotia Arc. As a consequence of this and subsequent submarine processes, this region shows a varied physiography. The new detailed map in the Drake Passage region is mainly founded on a compilation of precise multibeam bathymetric data obtained on cruises between 1992 and 2014, and covers the area between parallels 52ºS and 63ºS and meridians 70ºW and 50ºW. The new map that we present is based in a DTM with 200 m cell resolution of the seafloor in Drake Passage that permits identification of the main seafloor features and the map includes additional useful geological information. This work constitutes an international cooperative effort and is part of IBCSO project (International Bathymetric Chart of the Southern Ocean), under the SCAR umbrella.

Multibeam data from the southern Weddell Sea, Antarctica show three submarine slides on the upper slope of the Crary Fan, a large Trough Mouth Fan offshore from the glacially calved Filchner cross-shelf trough. These slides are the first Quaternary examples to be documented on an Antarctic Trough Mouth Fan and provide evidence for rarely observed submarine mass wasting on the Antarctic continental margin. Their occurrence contrasts many other previously glaciated continental margins, where mass wasting is common. All submarine slides head at the shelf edge (~500 m water depth), with two styles of mass wasting observed. The first style is characterised by a complex and wide (~20 km long) headwall, with a relief of 60 m and coverage of ~800 km2. Large, tabular slabs are observed down slope of the headwall. Two slides follow the second style of mass wasting. This style is characterised by a small, narrow and steep scarp at the shelf edge with increasing slide width (maximum 6 km) down slope. No large sediment deposits or lobes are observed down slope of these slides, although this may be limited by data extent. The large-scale differences in slide occurrence along the Antarctic continental margin suggest a significant variation in slope and sedimentary processes, environmental characteristics and/or glacial dynamics. It is likely that the slides are influenced by failure of weak layers within the subsurface, which may have been affected by rapid sediment transport and mass flow generation at the shelf edge, as indicated by widespread debris flow deposits observed in subbottom profiler data on the Crary Fan.