In recent years the term 'enhanced greenhouse effect' has become well known in modern society and yet aspects of this possible 'future climate' are poorly understood. The characteristics of the geological record provide a basis to understand this possible future climate through the examination of alternating glacial (cold) and interglacial (warm) stages. Understanding the variability of sea-surface temperature and biological processes in the water column provides insight into general circulation of present and paleo-ocean currents. The core obtained offshore from Sumatra (BAR9043, 104.0316E, 5.82S) highlights an upwelling signal at 14,000 yrs BP that disrupts the warm stratified water column, which was a feature between Marine Isotope Stage (MIS) 3 to present. This upwelling is timed to a regional pattern of an intensified Australasian Monsoon.
Sea-surface temperatures (SST) were estimated from planktonic foraminifera assemblage data using the modern analogue technique (MAT), in conjunction with the AUSMAT-F4 database. Each SST estimate was calculated as the mean of the best 10 analogues from the global database.
Sea-surface temperatures (SST) were estimated from planktonic foraminifera assemblage data. This has been collected for every 5cm of the core. The most precise variable of SST is mean annual temperature, followed by Tmax, then Tmin. All variables have a root mean squared error of prediction of less than 1 degree C. Most of the SST estimates are reasonably precise, given that the samples have good analogues in the AUSMAT-F4 database. Estimates do however become a little less precise towards the end of the core in MIS 3 (~30k BP).
Parameters: Age of core (yrs BP), mean water temperature (oC), maximum water temperature (oC), minimum water temperature (oC), depth of mixed layer (m), temperature at 50m, 100m and 150m (oC).
To investigate general palaeoceanographic conditions in the north-eastern Indian Ocean. This study was part of a larger undertaking to define the history of the Leeuwin Current to the West and South of Australia.
The Australian National University (ANU)
Funded by The National Oceans Office (NOO)
Funded by The Australian Research Council (ARC)
Funded by The French Polar Institute
Funded by The Australian Institute of Nuclear Science Engineering (AINSE)
Funded by The Murray Darling Basin Commission