Mega-pulses and megacycles in East Asian monsoon variations recorded in chinese loess-red clay magnetic susceptibility

Abstract

Three mega-pulses (first order variations) and four megacycles (second order variations) in loess-red clay magnetic susceptibility are identified in a loess section in the central Chinese Loess Plateau, implying pulsed fluctuations in East Asian monsoon intensity on tectonic timescales. Comparisons of the loess record with the mineral flux from ODP Site 758 and the diatom record in Lake Baikal core BDP-98 suggests that the loess-red clay magnetic susceptibility may represent a continental-scale signal of climate change. It is apparent that the stepwise-diachronous rise of the Tibetan Plateau and its resulting climatic influence may be the main cause of the observed monsoon pulses. Copyright 2006 by the American Geophysical Union.