Mechanism of Sea Level Change at the Earth Orbital Parameter Cycles during the Last 2 Ma BP

Li Wenbao; Wang Rujian

doi:10.3799/dqkx.2016.063

Abstract：Sea level change usually has great impact on global (or regional)ecological environment and social economy.Based on the published records of relative sea level (RSL),one new stacked RSL is reconstructed in this paper,and the correlations be-tween the new stacked RSL and original records are analyzed.In addition,the reliability and rationality of the new stacked RSL are tested and verified respectively by Spectrum and Filtering analysis.Furthermore,the evolutionary history and correlations between the stacked RSL and atmospheric CO 2 concentration,sea surface temperature (SST)in middle-high latitudinal oceans and benthic oxygen isotope (δ1 8 O B )record are separately discussed in detail.The results show that:(1)the new stacked RSL has the similar change trend to the original RSL records during the last 2 Ma BP,and the correlation coefficients are all nearly 0.9.Meanwhile,the new stacked RSL also responds well to the global climate change events at the earth orbital parameter cy-cles;(2)The new stacked RSL and LR04-δ1 8 O B have high negative correlation in glacial-interglacial cycles during the last 2 Ma BP,with the correlation coefficient of about 0.81,which is much higher than those of the new stacked RSL with SST and at-mospheric CO 2 concentration;(3)Based on the cross-spectral analytical results between the new stacked RSL and CO 2 ,SST andδ1 8 O B ,individually,the new stacked RSL is nearly in phase withδ1 8 O B ,and both lags SST and CO 2 at the eccentricity band,and lags SST but leads CO 2 at the obliquity band.It is concluded that the polar ice sheet volume was influenced by chan-ges of SST and atmospheric CO 2 concentration,which might be caused by the change of solar insolation and finally influenced the sea level change at the earth orbital parameter cycles.