We are collecting high-resolution multi-channel seismic (MCS) profiles and sediment cores from sites in the western equatorial Pacific. Each site supports the survey and site evaluation needs of IODP proposal 799 whose goal is to extend the record of millennial climate variability back to the mid Miocene. We are using the R/V Revelle and its high-resolution MCS gear to survey and core sites in the heart of the western Pacific Warm Pool (WPWP). These include a potentially high-sedimentation site due east of Mindanao, Philippines, low-sedimentation rate sites from the Carolina Ridge, Eauripik Rise and northern Manus Island (a N-S transect between 8°N and 2°S) and in the eastern part of the WPWP, high sedimentation sites on the southern side of Manus Island and near the Sepik River estuary. The seismic survey will be done in keeping with the Guidelines of the IODP Site Survey Panel (SSP).
Paleoclimate records from the equatorial Pacific have offered new insights into mechanisms of climate change and helped in testing climate models that are used for the IPCC predictions. Exciting discoveries have recently been made by the analysis of high-sedimentation rate sediment cores in this region, providing important insights on millennial-scale climate variability of the East Asian Monsoon (EAM) system over the past 70 kyr and on deep ocean ventilation. Several sites we are surveying will fill gaps in equatorial Pacific data sets, namely the lack of high-resolution records from the eastern part of the WPWP, that match the resolution of Greenland ice cores, and can help in evaluating the controls on the hydrologic cycle in the WPWP and a limited meridional coverage to test hypotheses related to the Plio-Pleistocene evolution of the WPWP.