HR: 17:00h
AN: PP24A-05    [Abstracts]
TI: Long Terrestrial Paleoenvironmental Records From Beringia
AU: * EDWARDS, M
EM: M.E.Edwards@soton.ac.uk
AF: UNIVERSITY OF SOUTHAMPTON, SCHOOL OF GEOGRAPHY HIGHFIELD, SOUTHAMPTON, SO17 1BJ United Kingdom
AU: * EDWARDS, M
EM: M.E.Edwards@soton.ac.uk
AF: UNIVERSITY OF ALASKA, INSTITUTE OF ARCTIC BIOLOGY, FAIRBANKS, AK 99775 United States
AB: Several records of vegetation change extending from MIS 5 to the present, and others covering various parts of the last glacial-interglacial cycle, have been retrieved from both west and east Beringa (Siberia and Alaska). Recently, analogue analysis has produced quantitative estimates of past climate conditions. Records from Beringia show several consistent patterns that differ from those observed in the North Atlantic sector. The last interglaciation (MIS 5), while seeing a greater extension of forest cover than the Holocene (and possibly greater reduction of permafrost), does not appear to have exceeded Holocene temperature values to the extent recorded for the North Atlantic region. The tripartite nature of stage 5 warm periods, strong in Europe, is muted in Beringia, and records of glacial stages are not generally characterized by rapid, high-amplitude fluctuations. A climatic oscillation during the Younger Dryas chronozone is apparent at several sites: the signal is subtle in interior regions, stronger at the coast. The Holocene thermal maximum occurred early, ca 9-11 ka BP. Colder periods appear to have been characterized by extreme aridity, and moisture availability has been an important control of terrestrial ecosystem structure and function through much of the last glacial-interglacial cycle. The regional response of Beringia to global and hemispheric forcing primarily reflects its location upwind of the Laurentide ice and the dynamics of the northern Pacific and western Arctic oceans (especially those of sea ice). Events generated in the North Atlantic are generally not strongly expressed, though some are detectable.
DE: 1620 Climate dynamics (3309)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting