Glacial stage ice-core records from the subtropical Dunde ice cap, China

Abstract

The first ice-core record of both the Holocene and Wisconsin/Wurm Late Glacial Stage (LGS) from the subtropics has been extracted from three ice cores to bedrock from the Dunde ice cap on the north-central Qinghai-Tibetan Plateau. Ice thicknesses at the ice-cap summit average 138 m, the bedrock surface is relatively flat, surface and basal temperatures are -7.3 and -4.7°C, respectively and the ice cap exhibits radial flow away from the summit dome. These records reveal a major change in the climate of the plateau ~10 000 years ago and suggest that LGS conditions were colder, wetter and dustier than Holocene conditions. Total β radioactivity from shallow ice cores indicates that over the last 24 years the average accumulation rate has been ~400 mm a-1 at the summit. The oxygen-isotope record which serves as a temperature proxy indicates that the last 60 years have been the warmest in the entire record. -from Authors