Holocene Climate Changes Recorded in an East Antarctica Ice Core

Abstract

Ice core derived proxy climate records from Antarctica suggest that decadal, century and possibly even millennial-scale temperature variations in East and West Antarctica may be temporally asynchronous. For example, records from the Antarctic Peninsula indicate a strong 20th century warming in which the high plateau of East Antarctica has not participated. Similarly, a recent Neoglacial cooling, the “Little Ice Age”, was prominent in East Antarctica, but absent in the Peninsula region. A new history of oxygen isotopic ratios (δ18O) and atmospheric dust concentrations from central East Antarctica suggests that the high inland plateau has been dominated by a cooling trend for the last 4000 years. Superimposed upon this isotopically-inferred cooling were a number of warmer events, the largest and most persistent of which occurred ≈ 3600 yr. BP and lasted several centuries. The most prominent event is a prolonged cold phase around 2200 yr. BP which is correlative with a mid-Neoglacial advance on South Georgia Island (Clapperton et al, 1989). Most intriguing are several shorter-term (multi-centennial scale) δ18O oscillations which are similar in magnitude to the glacial-interglacial transition in Antarctic ice cores. Although it is impossible to discount the effect of wind scouring and re-deposition in this low snow accumulation region, this 4000-year history raises important questions about the climate history on the high inland plateau during the last half of the Holocene. Certainly, a better spatial distribution of high resolution δ18O records from East Antarctica are necessary to determine the extent to which the Plateau Remote record is spatially representative.