Abstract

Quaternary rainfall reconstructions for the monsoon-dominated region of East Asia remain both of critical importance for testing general circulation model estimates of past and future rainfall for this populous region, and intensely debated. The oxygen isotope variations of the well-dated Chinese speleothem records have been very widely perceived as proxies of summer monsoon intensity and summer rainfall totals. Mass balance calculations demonstrate that extremely large changes in rainfall are required in order to generate the magnitude of oxygen isotope variations seen both within the Holocene and over glacial and interglacial timescales throughout the Quaternary. Rainfall proxy records derived from the famous loess/palaeosol sequences of the Chinese Loess Plateau do not accord with the cave records (and are rarely if ever discussed by the cave science community). Here, the key areas of debate will be explored. The possible dominance of Pacific- rather than North Atlantic-sourced influences on the East Asia monsoon will also be discussed.

A Quaternary Discussion Group seminar