AKADEMIYA NAUK ESTONSKOI SSR TARTU INST OF GEOLOGY
The Arctic holds extensive records of past climatic and environmental changes. Stable isotope variations in polar ice are in many cases important records of paleoclimatic information. Deep ice cores from Antarctica and Greenland, reaching back through the last glaciation, have provided valuable information about the Earths climate in the past. This paper discusses the oxygen-18 variations in intermediate-depth ice cores from smaller ice caps of Svalbard, Severnaya Zemlya North Land and from the marginal area of the Antarctic ice sheet, covering the time span from 1000 to 8000 years B.P. All profiles studied clearly reflect the main climatic events during this time interval. However, small shifts in time exist between details on different curves. Most probably this is due to certain asynchronity in climatic changes in the various regions. There are extensive areas in the Arctic, especially in its eastern sector, where no glaciers currently exist and, possibly, in some areas never existed in the past either. These are the areas of permafrost where several forms of ice occur Within the ground. The source water for most types of ground ice originates from precipitation, but unlike glacier ice, the range of mechanisms for the formation of ground ice is very large, which considerably complicates the interpretation of their isotopic characteristics. For paleoclimatic and paleopermafrost reconstructions, the isotopic content of polygonal wedge ice seems to be most promising. The attempts to use isotopic records from segregated ice for paleoenvironmental research will also be discussed.
This article is from 'Proceedings of the International Conference on the Role of the Polar Regions in Global Change Held in Fairbanks, Alaska on 11-15 June 1990. Volume 2', AD-A253 028, p611-616. See also Volume 1, AD-A253 027.