Glacial-Holocene paleoceanography of the western equatorial Pacific: Carbonate dissolution and sea surface temperatures in the south China and Sulu Seas

Conference · Wed Jan 01 04:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5690512

Miao, Qingmin; Thunell, R C ^[1]

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1. Univ. of South Carolina, Columbia, SC (United States). Dept. of Geological Sciences

Six sediments cores from the South China Sea (SCS) and four from the Sulu Sea (SS) have been used in a detailed study of sea surface temperature changes in these two basins during the last 25,000 year. Sea surface temperature (SST) estimates were derived using a planktonic foraminiferal transfer function (FP-12E). The water depths for the cores range 500 m to more than 4,000 m. The time series (SST) records indicate that winter and summer temperatures during the Holocene were approximately 27 C and 29.5 C, respectively, for both the (SC) and (SS). During the last glacial maximum, summer sea surface temperatures were approximately 28.5 C in the (SCS) and 29 C in the (SS), and thus very similar to the Holocene. In contrast, glacial winter (SST) are estimated at 21 C for the (SCS) and 24 C for the (SS). This decrease in glacial winter (SST) results in a much larger seasonality during the last glacial compared to the Holocene. Variation in intensity of the monsoon system and surface water exchange rates between basins are the major factors controlling glacial-interglacial SST fluctuations in the (SC) and (SS). The primary factor influencing the accuracy of the SST estimates is the quality of preservation of planktonic foraminiferal assemblages. Results show that increasing levels of dissolution result in systematically cooler SST estimates. This is due to the fact that warm water foraminifera tend to be more solution susceptible and as dissolution progresses the assemblage becomes enriched in the more resistant, cool water taxa. Since dissolution is more intense during interglacials than glacials in the Pacific, dissolution tends to reduce the amplitude of the true glacial-interglacial temperature difference.

• OSTI ID: 5690512
• Report Number(s): CONF-921058--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 24:7
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CARBONATE ROCKS
CENOZOIC ERA
CHINA SEA
DISSOLUTION
DRILL CORES
GEOLOGIC AGES
GLACIERS
OCEANOGRAPHY
PACIFIC OCEAN
PALEOCLIMATOLOGY
PALEONTOLOGY
PALEOTEMPERATURE
QUATERNARY PERIOD
ROCKS
SEAS
SEASONAL VARIATIONS
SEDIMENTARY ROCKS
SURFACE WATERS
VARIATIONS