2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 163-4
Presentation Time: 1:50 PM

THE ANTARCTIC PENINSULA FJORD SEDIMENT RECORD: A REGIONAL EVALUATION OF GLACIAL RESPONSE TO HOLOCENE CLIMATE EVENTS


MINZONI, Rebecca L., Earth Science, Rice University, 6100 Main Street, Houston, TX 77005, ANDERSON, John B., Department of Earth Science, Rice University, 6100 Main Street, Houston, TX 77005, WELLNER, Julia S., Department of Geosciences, University of Houston, 312 Science & Research Building 1, Houston, TX 77204-5007 and FERNÁNDEZ, Rodrigo A., Jackson School of Geosciences, U.T.I.G. - University of Texas Institute for Geophysics, J.J. Pickle Research Campus, Bldg. 196, 10100 Burnet Road (R2200), Austin, TX 78758-4445, rlt1@rice.edu

Over three decades of seismic and coring efforts in Antarctic Peninsula (AP) fjords have yielded an extensive database of stratigraphic information and glacimarine sediment records, which together reveal a complex history of glacial behavior following the Last Glacial Maximum. Here we present new and updated records from fjords and bays of vastly different climatic and oceanographic settings and glaciological configurations in order to better understand the variability of AP glacial response during known climate events, such as the Mid Holocene Climatic Optimum and the Late Holocene Neoglacial. Paleoclimate records are obtained by conducting high-resolution (every ~40-150 years), multi-proxy analyses on well-dated cores, including: grain size, magnetic susceptibility, diatom and foraminiferal assemblages, organic carbon content, and in some cases stable isotopes. This study builds on the published record by re-sampling cores for additional proxies and adding new study areas which meet the criteria of having expanded Holocene stratigraphy and well-constrained chronology. Study areas include: Herbert Sound, Firth of Tay, Maxwell Bay, Lapeyrère Bay, Neny Fjord, and Ferrero Bay of the Amundsen Sea for comparison with polar environments. These records are scrutinized closely with the Late Pleistocene-Holocene ice core from James Ross Island (<20 km from Herbert Sound), as well as with marine records from Palmer Deep and Bransfield Basin. This comparison reveals that both initial fjord deglaciation and response of tidewater glaciers to major warm events were characterized by great variability in timing and magnitude across the peninsula, whereas response to cool events, such as the Late Holocene Neoglacial, was broadly synchronous and lacked substantial expression of glacial advance in marine basins. An important outcome of this research is improved understanding of the current warming trend in the AP and how it compares with Holocene climate events. Ongoing research is aimed at addressing the manifestation of recent warming and deglaciation in the fjord sediment record.