Climatic effects of late‐glacial surges based on the example of the 10,500 b p: Cold phase

Abstract

A map of paleotemperature anomalies at 10,500 B.P. for the North Atlantic and adjacent continents was compiled. It is based upon data from marine micropaleontological and palynological studies. The pattern of isotherms reveals that maximum negative anomalies occurred in the eastern subtropical North Atlantic between 35 and 45°N, reaching values of 8–9°C, i.e., double those recorded over the adjacent landmasses (2–4°C). The area of maximum lowering of sea surface temperatures was located only some 5° south of the zone of highest accumulation rates of iceberg‐rafted sands. On land the area of maximum cooling coincided with the zone affected by Mediterranean cyclones. In the eastern part of the ocean, off the European and African coasts the sea surface isotherms diverged northwards and southwards, suggesting that there was a bifurcation in a westerly cold current at the latitude of about Lisbon. All these features are inconsistent with “traditional”; concepts of paleotemperature anomalies associated with astronomically induced climatic changes, but they agree well with the conceptual model of spatial sea surface temperature anomalies caused by massive late‐glacial discharge of icebergs into the ocean.