PP11D-06
The Lake Towuti Drilling Project: A New, 1-Million Year Record of Indo-Pacific Hydroclimate

Monday, 14 December 2015: 09:15
2012 (Moscone West)
James M Russell1, Satria Bijaksana2, Hendrik Vogel3, Martin Melles4, Sean Crowe5, Silvia J Fajar2, Ascelina Katharina Hasberg4, Sarah Ivory1, Jens Kallmeyer6, Christopher Sean Kelly1, Kartika Hajar Kirana2, Marina Morlock3, Gerald H Tamuntuan2, Satrio A Wicaksono1 and Scientific Team of the Towuti Drilling Project, (1)Brown University, Providence, RI, United States, (2)Bandung Institute of Technology, Bandung, Indonesia, (3)University of Bern, Bern, Switzerland, (4)University of Cologne, Cologne, Germany, (5)University of British Columbia, Vancouver, BC, Canada, (6)Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany
Abstract:
­The Indo-Pacific region plays an integral role in the Earth’s climate system. Changes in local insolation, greenhouse gas concentrations, ice volume, and local sea level are each hypothesized to exert a dominant control on Indo-Pacific hydroclimate variations through the Pleistocene, yet existing records from the region are generally short and exhibit fundamental differences in orbital-scale patterns that limit our understanding of the regional climate responses to these global forcings. New paleoclimate records spanning multiple glacial-interglacial cycles are therefore required to document the region’s hydroclimatic response to the full range of global climate boundary conditions observed during the late Quaternary.

Lake Towuti is located in central Indonesia and is the only known terrestrial sedimentary archive in the region that spans multiple glacial-interglacial cycles. From May – July, 2015, the Towuti Drilling Project, consisting of nearly 40 scientists from eight countries, recovered over 1,000 meters of new sediment core from Lake Towuti. This includes cores though the entire sediment column to bedrock, which likely provide a >1-million-year records of regional hydroclimate. On-site borehole and sediment core logging data document major shifts in sediment composition, including transitions from lake clays to peats, calcareous sediments, and gravels. These data show excellent agreement with major lithological transitions recorded in seismic reflection data, and indicate large changes in lake levels and hydroclimate through the late Quaternary. Prior work on Lake Towuti indicated a dominant control by global ice volume on regional hydroclimate, a hypothesis we aim to test through the analysis of these new cores. This presentation will review existing records from the region and show the first long geochemical and sedimentological records from Lake Towuti to understand orbital-scale hydrologic change during the last ~1 million years.

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