After we reached on our forths day, Friday 19th April, the deep-sea area to the south-west of South Georgia, we started very early Saturday morning the Parasound survey of the sediment waves. These sediment waves, which are thought to have formed through bottom currents, document through high sedimentation rates the Palaeo-oceanography of the Circum-Antarctic Current and were therefore chosen as targest for sampling. We sampled these structures via two gravity corer and one multicorer deployments throughout Saturday despite a lively sea state and winds of 6 to 7 on the Beaufort scale. Multi-proxy examinations at the AWI on these sediment cores shall deliver new knowledge on the temporal variability of the surface and seafloor circulation during the last orbital climate cycle. The oceanographic regions around South Georgia are of special interest for Palaeo-oceanography because of the possibility of iron influx and a linked raised primary productivity. On Sunday, 21st April, the weather was to brigthen and calm down and we planned our first dive with the MARUM ROB QUEST to dive at Paradise Flare and investigate a gas emission site (Fig. 2). Paradise Flare was discovered in the course of hydroaccoustic surveys of the water column during the RV Meteor Expedition M134 in 170 m water depth in 2017 but bad weather had stopped a closer investigation.

Again, weather conditions on Sunday and Monday denied us the chance of a detailed investigation of the site. But we were able to use the new multi-function sledge OFOBS of the AWI deep-sea group at the location and next to an optical assessment in the neighbourhood of Paradise Flare do a bathymetric survey of the seafloor with the sledge’s side-scan sonar (Fig. 3). In the afternoon of Easter Sunday, we steamed into Drygalski Fjord, which is penetrating deep into the island at the southeasterly end of South Georgia. While the entrance to the fjord is 2 km wide, it narrows to just about 800 m width, and from board of RV Polarstern one had a fantastic view to the steep mountain sides, the glaciers, and onto the geological fomations formed by the oldest rocks of South Georgia. Right in the middle of the fjord, we took a sediment core within a tightly confined basin, which chemical signature is of special interest to our geochemists. The sampling was a success. The evening of Easter Sunday was celebrated with a BBQ on the working deck and in the working deck-level, inner cargo hold of RV Polarstern.

Unfortunately, Easter Monday, 22nd April, was, like expected, still too stormy to proceed with our first dive at Paradise Flare. Therefore, we used the day for a series of sediment cores by gravity corer in various sub-basins of the Drygalski Trough and by a multicorer with 12 shorter sediment cores. Thick sediment layers in some of the fjords and glacially eroded troughs of South Georgia have exceptionally well archived recent galcier behaviour and climate change. The sub-polar ice-cap on South Georgia reacts more sensitive to climatic changes than the much larger and more isolated Antarctic ice shelves and are therefore a central targed for studies on sediment cores to better understand the climate variations in the Southern Hemisphere. Unfortunately the weather system will allow us commence the first dive earliest on Wednesday and therefore we decided to use the Tuesday to steam to the East Scotia Ridge, to start our diving there on the hydrothermal vents of the ridge segment E2. A westerly wedge of a high pressure system lying to the north will reach us and is promising a few calmer days, which we want to use for ROV dives.

Apart from a few scientists sharing a mild cold, everybody else is fine.

Best regards in the name of all participants,

Gerhard Bohrmann -  FS POLARSTERN Monday, 22nd April 2019