As part of a programme dealing with the extent of ice sheets in northern and arctic Europe during the latest (Weichsel, Wiirm, Wisconsin) glaciation the Department of Physical Geography, University of Stockholm, from 1957 until the early 1970's, undertook a series of expeditions and field trips to different parts of the Svalbard archipelago. A main result of these investigations was an isobase map demonstrating land-uplift during the last 6 500 years; the 6 500 BP reference date being chosen because of the abundance of datable raised strandlines formed at that time. The uplift area is centered east of Spitsbergen and southeast of Nordaustlandet, and is believed to represent rebound from glacio-isostatic depression caused by an extensive ice-sheet over Svalbard and adjoining parts of Barents Sea during Weichsel time (Schytt, Hoppe, Blake and Grosswald 1968, Hoppe 1971). The idea of a vast ice-sheet in the Arctic during the Weichsel time was not totally new when we first presented it in the late 1960's. However, earlier presentations were based on rather weak arguments, if any. Since our early publications, numerous papers have appeared dealing with the same subject and arriving at very different conclusions, both as to the extent of the glaciation and as to the time of its maximum. For these reasons a special programme of further study, with data sampling from both land and sea bottom, was included in the Swedish Arctic Expedition YMER-80, undertaken in the summer of 1980.