Title:
Using cave monitoring and speleothems to unravel hydroclimate variability in the Indo-Pacific Warm Pool through the Quaternary
Abstract:
Understanding hydroclimate dynamics in Southeast Asia across millennial scale events is essential for evaluating long-term Indo-Pacific climate variability. In this talk, I will first present ongoing cave monitoring results from three different cave systems across the Philippines. I will show why continuous and long-term cave monitoring is critical for understanding how climate and in-cave processes control modern cave microclimate and the geochemistry of cave drip waters and modern calcite. Cave monitoring results including CO2 measurements, daily drip rate, and drip water and modern cave calcite geochemical data will help develop site specific relationships between climate and subsurface geochemistry. The second part of the talk will focus on late Pleistocene hydroclimate variability in the Philippines. We have 5 multi-proxy uranium-series dated speleothem records from the Philippines: from Palawan (Puerto Princesa Subterranean River, Natuturingam Cave, stalagmite GG-1; ~68–96 ka BP, MIS 5b–4; and overlapping stalagmites GP-0, GP-1 and GP-3, ~4-48 ka BP, MIS 2-3) and Bohol (Hinagdanan Cave, stalagmite BH1; ~28–51 ka BP, MIS 3). I will solely focus on the BH1 speleothem to reconstruct tropical hydroclimate dynamics using stable isotope and trace element geochemistry to decouple local versus regional hydroclimate variability. BH1 reflects rapid oxygen isotope and trace element shifts occur during HS 3 and 4 but not HS 5. This will be placed in the context of other speleothem records from the region to provide new constraints on abrupt teleconnection mechanisms in the Indo-Pacific Warm Pool
