HR: 11:20h
AN: PP32A-05    [Abstracts]
TI: Be-10 dating of historical glaciations in the Southern Alps of New Zealand
AU: * Schaefer, J M
EM: schaefer@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, Route 9W, Palisades, 10964, United States
AU: Denton, G H
EM: gdenton@maine.edu
AF: University of Maine, Department of Earth Sciences and Climate Change Institute, Orono, 04469, United States
AU: Schluechter, C
EM: schluechter@unibe.ch
AF: University of Berne, Baltzerstrasse 1, Berne, 3012, Switzerland
AU: Barrell, D
EM: D.Barrell at gns.cri.nz
AF: GNS Science, 764 Cumberland Street, Dunedin, 9054, New Zealand
AU: Finkel, R C
EM: finkel1@llnl.gov
AF: UC Berkeley, Main Campus, Berkeley, CA 94720,
AU: Andersen, B
EM: schaefer@ldeo.columbia.edu
AF: University of Oslo, Blindern, Oslo, NOR 0317,
AU: Putnam, A
EM: Aaron_Putnam@umit.maine.edu
AF: University of Maine, Department of Earth Sciences and Climate Change Institute, Orono, 04469, United States
AU: Kaplan, M
EM: mkaplan@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, Route 9W, Palisades, 10964, United States
AU: Schwartz, R
EM: roseanne@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, Route 9W, Palisades, 10964, United States
AB: Understanding the natural variability of climate change during the Holocene period is key to correctly evaluate the ongoing climate change. Glaciers are among the most sensitive recorders of climate changes, and deposited spectacular Holocene moraine sequence in many areas on Earth. The moraine record of New Zealand's Southern Alps offers the unique opportunity to reconstruct in detail Holocene glaciations in southern mid-latitudes, an area where paleo records are particularly sparse. At least five Holocene glaciations have been mapped in several mountain glacier systems. However, until now a uniform and reliable dating tool for Holocene moraines has been missing. Due to very recent methodological progress, glacial advances throughout the Holocene period including the historical time-scale can now be accurately dated by Be-10 surface exposure dating. We present more than 50 Be-10 boulder ages from Holocene moraines deposited by the Hooker, Muller, and Tasman glacier in the Lake Pukaki area spanning the last 6,000 years, including three glacial events during the last millenium. The cosmogenic chronology is of high internal consistency and shows that glaciations during the latest part of the Holocene period in the Southern mid-latitudes differ from the pattern known from northern latitudes.
DE: 1150 Cosmogenic-nuclide exposure dating (4918)
DE: 1827 Glaciology (0736, 0776, 1863)
DE: 4914 Continental climate records
DE: 4918 Cosmogenic isotopes (1150)
DE: 4926 Glacial
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting