魏國彥2006-07-252018-06-282006-07-252018-06-282004http://ntur.lib.ntu.edu.tw//handle/246246/11841Using Mg/Ca ratios of planktonic foraminifer Globigerinoides sacculifer and alkenone unsaturation index of bulk sediments from the deep-sea core MD972142, we reconstructed sea-surface paleotemeratures of the past 165 thousand years for the southeastern South China Sea near the Palawan Island. The paleo-SSTs fluctuated between ~24 o C and 29 o C through the past two glacial-interglacial cycles with the coldest SSTs of ~24 o C at the last glacial maximum. The SSTs during the late Holocene are comparable to the peak values of the marine oxygen isotope stage 5. To examine the salinity/hydrographic variation, the effects of temperature and ice-volume were subtracted from the δ 18 O values of planktonic foraminifer Globigerinoides sacculifer. The resultant residual δ 18 O profiles indicate that the surface oceans have been fresher than today’s for most of the time during the past 165 thousand years. In general, during the low sea-level periods in glacial stages, the corrected δ 18 O values tend to deviate from the current value, signifying various degrees of freshening. Contrarily, when the sea-levels were high, the surface waters tend to be as salty as it is today. Nevertheless, at millennial scale, the surface waters were more stratified during the interstadial than in the stadial intervals due to stronger fresh-water input and higher surface temperature.application/pdf313099 bytesapplication/pdfzh-TW國立臺灣大學地質科學系暨研究所South China SeaSSTsHydrographPaleotemperature[SDGs]SDG14reporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/11841/1/922116M002008.pdf