Monday, 27 August 2007
1.PS-8
New approaches and progress in the use of polar marine diatoms in reconstructing sea ice distribution
Amy Leventer, Geology Department, Colgate University, 13 Oak Drive, Hamilton, NY 13346, Leanne Armand, Laboratoire d’Oceanologie et de Biogeochimie, Centre d’Oceanologie de Marseille, Campus de Luminy, case 901, F-13288, Marseille, France, David Harwood, Department of Geosciences, University of Nebraska--Lincoln, 214 Bessey Hall, Lincoln, NE, NE 68588-0340, Ric Jordan, Department of Earth and Environmental Sciences, Yamagata University, Yamagata 990-8560, Japan, and Ryszard Ligowski, Institute of Biology, Swietokrzyska Academy, Swietokrzyska 15, 25-406 Kielce, Poland.
Reconstructing the paleo-latitudinal extent of sea ice in the Southern Ocean over time can be accomplished using modern diatom data. However, it is more difficult to extend the utility of diatom proxies farther back in time, to time periods characterized by species that are now extinct, since we are uncertain of the paleoenvironmental affiliation of those species we can’t observe in modern assemblages. We propose several research strategies to strengthen our ability to use diatom data to reconstruct sea ice history. These tactics include the evaluation of specific morphologic characteristics and distinct taxa, as well as the identification of specific adaptations that may have evolved following the initiation of sea ice in the Southern Ocean. In particular, we note that the evolution of resting spores and winter growth forms should be studied more thoroughly.