EuroSpeleo 2016

Amplitude and pacing of abrupt climate change: derived from Asian stalagmite records spanning the last 70ka

Oral|Ms Xiumin Zhai

Abstract

Abrupt millennial events characterized the last glacial period. Weak monsoon events in the East Asian monsoon zone have an obvious low latitude precession cycle strongly distinct from the 100ka period of the northern high latitude ice sheet. Investigation of the pacing and amplitude of these events is an important approach for uncovering the underlying forcing mechanisms. Intact and continuous speleothem 18O records from the last 70ka were constructed, based on two stalagmites from Luoshui Cave in a karst gorge near Lichuan city, Hubei province. The two stalagmite 18O records replicate well in terms of pattern and amplitude with regard to the millennial events. Abrupt millennial events over the last glacial period and the Holocene were compared in pacing and amplitude, and we attempted to calculate the relative contributions of low latitude precession and the high latitude ice sheet to the amplitude of the abrupt millennial events in the East Asian monsoon zone. These studies shed light on the underlying mechanisms for abrupt millennial events over the last glacial period, and they help unravel the relationship between pacing and amplitude of these abrupt events, and solar insolation.