Southern Ocean and Antarctic Peninsula Temperatures During Critical Climate Transitions of the Cenozoic Constrained by Clumped Isotope Thermometry

Friday, 19 December 2014
Ryan Dill1, Robert Eagle1, Drew Henry2, Samantha Praskin1, John Arthur Mering1, Victoria A Petryshyn1, Antra Priyadarshi1, Lydia Rycroft1,3, Tyler Vollmer1, Yung Chea1,3, Jamie Dix1, Alejandro Aguilar1, Kevin Supakkul1,4, Ben Tran1,5, Zachary Lipel1,6, Steve Flores1, Christina R Riesselman7, Marco Taviani8, Sergio Marenssi9, David M Harwood10, Dan John Lunt11, Paul J Valdes11, Anna Nele Meckler12 and Aradhna Tripati13, (1)University of California Los Angeles, Department of Earth, Planetary, and Space Sciences, Los Angeles, CA, United States, (2)University of California Los Angeles, Los Angeles, CA, United States, (3)Imperial College London, London, United Kingdom, (4)Colleyville Heritage High School, Colleyville, TX, United States, (5)Westlake High School, Westlake Village, CA, United States, (6)North Hollywood High School, Los Angeles, CA, United States, (7)University of Otago, Dunedin, New Zealand, (8)Institute of Marine Science, ISMAR-CNR, Bologna, Italy, (9)Instituto Antártico Argentino, Buenos Aires, Argentina, (10)University of Nebraska Lincoln, Lincoln, NE, United States, (11)University of Bristol, Bristol, United Kingdom, (12)ETH Swiss Federal Institute of Technology Zurich, Zurich, Switzerland, (13)UCLA, Los Angeles, CA, United States
The Southern Ocean and Antarctica play fundamental roles in the global climate system. These polar regions are a major area for the net loss of heat to space. Ice storage on Antarctica also influences the global water cycle. Through upwelling of deep waters, the Southern Ocean is an important regulator of atmospheric CO2. To better constrain the evolution of paleoclimate in this region over major climate transitions of the Cenozoic, we estimated ocean temperatures using clumped isotope thermometry. Clumped isotope thermometry is a thermodynamically-based stable isotope thermometer that can be used to constrain temperatures previously estimated using other paleothermometers (which in turn leads to constraints on ice volume), as it allows the exclusion of water isotope composition from temperature estimates (unlike the ╬┤18O thermometer). We previously have published calibrations for foraminifera and mollusks, two of the major archives used in this study. Critical transitions investigated include the Eocene-Oligocene boundary and the Middle Miocene Climate Transition. Study sites include Seymour Island (Antarctic Peninsula), ANDRILL (Southern McMurdo Sounds), Ocean Drilling Program (ODP) Sites 689/690 (Weddell Sea), and ODP 744 (Kerguelen Plateau). Results will be compared to GCM output.