Svalbard-Barents Sea Ice Sheet

The Svalbard-Barents Sea Ice Sheet (SBSIS) covered not only the Svalbard Archipelago, but also large parts of the current Barents Sea. During strong glacials, it reached the Scandinavian Ice Sheets towards South, and Frans Josef Land and Novaya Zemlya towards east and southeast, reaching even into the Kara Sea. The thick ice mass shaped the buried landscape and left traces at many locations. Today, we are able to read those traces and reconstruct past extent and dynamics of the SBSIS. The most prominent ones are the glacial troughs around Svalbard that host the beautiful fjords. Such troughs indicate areas of fast-flowing ice with enough force to severely erode the landscape. Similar troughs are not only located around Svalbard, but also in many areas of the shallow shelf. 

We also find traces that mostly originate from the decay and retreat of the ice mass. These include moraines as we know them from mountain glaciers. But the decaying ice sheet also calves icebergs that, if large enough, reach the ocean floor with their keels and leave imprints. When these icebergs melt later on on their journey. they release pebbles and sand grains that got incorporated during their formation. We use bathymetry to map the ocean floor and learn about iceberg movements at the end of the last glacial. To look further back in time, i.e., the last interglacial and previous glacials and interglacials, we use sediment echography and seismics to image the sub-seafllor. We also take sediment cores that we investigate with further measurements. For example, by counting the pebbles and sand grains that were transported by ice, we gather information about times when ice sheets decayed. Some pebbles and sand grains are even indicative for their origin, which helps us to reconstruct past ocean currents from the iceberg drift.

The Barents Sea - the ocean basin north of Scandinavia - was subaerially exposed until ca. 1 million years ago. The thick SBSIS, however, eroded the area heavily, making the area a shallow ocean basin. The change from land to sea had massive consequences for the ocean currents in this area.

We currently investigate bathymetry, sediment echosounder, and seismic data, but in addition we also use long sediment cores that were drilled west off Svalbard in an international effort - IODP Expedition 403. These drill cores reach back in time beyond the onset of the major Northern Hemisphere glaciations and will teach us about the paleoclimate evolution and about past ocean currents of the past ca. 5 million years.