ON THE NATURE OF THE ICE CAP ON THE TIBETAN PLATEAU DURING THE LATE QUATERNARY

Considerable debate persists among scientists interested in the nature of the ice cap on the Tibetan Plateau during the late Quaternary. We examine the implications, on this problem, of the high resolution data that has recently become available from the Dunde ice cap in north Tibet. The observed -2% parts per thousand change in the delta-O-18 of the ice formed at the Dunde ice cap during the Last Glacial Stage (LGS) suggests a limit in the range of 5-7-degrees-C on the reduction in annual surface air temperature over Tibet during the LGS. This then translates to an Equilibrium Line Altitude (ELA) lowering of 700-1200 m. Due to this lowering, ELA could have reached below the level of the surface of the plateau resulting in an extensive ice sheet formation during LGS.