|
|
Abstracts
SEARCH Open Science Meeting
October 27, 2003
Seattle, Washington, USA
Lightweight Shallow Ice Coring and Borehole Logging Can Provide Decadal- to Millenial-Scale Indicators of Climate Change Around the Arctic Basin
Robert L. Hawley1, Edwin D. Waddington2, Joseph R. McConnell3, Dale P. Winebrenner4
1Earth and Space Sciences, University of Washington, 63 Johnson Hall, Seattle, WA, 98195, USA, Phone 206-616-5393, Fax 206-543-0489, bo@u.washington.edu
2Earth and Space Sciences, University of Washington, Box 351650, Seattle, WA, 98195, USA, Phone 206-543-4585 , Fax 206-543-0489, edw@geophys.washington.edu
3Desert Research Institute, University of Nevada, 2215 Raggio Parkway, Reno, NV, 89512, USA, Phone 775-673-7348, Fax 775-673-7363, jmcconn@dri.edu
4Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, WA, 98195, USA, Phone 206-543-1393, Fax 206-616-3142, dpw@apl.washington.edu
Data from coring and borehole logging in ice caps (large or small) can add significant value to climate research programs by providing a longer time-scale view of important climatic indicators. While the length of the instrumental record is limited to about 100 years, the length of the paleoclimate record from ice cores is limited only by the depth and relative accumulation rate of the ice-core site. For example, shallow (250 m) coring programs on the Devon Island Ice Cap have recovered annual- to decadal-resolution climate records more than 5000 years long while recent NASA-funded shallow and intermediate coring on the Greenland Ice Sheet has provided detailed spatial records of net accumulation and glaciochemistry over recent decades to centuries.
A new generation of lightweight drills for shallow coring allows a shallow (~10-50 m) ice core to be drilled, logged, and packed in a single day, and intermediate-depth cores (50-200 m) to be taken in a week. New continuous-melter analysis techniques allow rapid high-resolution precisely-coregistered multiparameter chemical analysis. The hole "left over" from the coring effort can be logged with various tools to further our understanding of past climate.
In particular, Borehole Optical Stratigraphy (BOS) is a technique for rapidly logging optical properties in ice which are directly linked to climate indicators. Using BOS, we can identify annual layers and melt horizons in an icecap, measure vertical motion in the ice, and potentially determine a density and grain-size profile. This information can be related to useful quantities for paleoclimate modeling such as temperature and precipitation. Chemical analyses of the extracted core can also provide paleoclimate time series, and together, all these techniques can provide a comprehensive picture of past climates, including both averages and extreme events.
A pan-arctic coring and logging program could efficiently extract paleoclimate records from many ice caps around the arctic basin, allowing analysis of the spatial patterns of paleoclimate. Within a single icecap, multiple coring sites can accurately characterize local climate zones, and gradients related to regional weather patterns and storm tracks, in order to place that ice cap in the context of the arctic as a whole.
Abstract Categories: Changes on Land, Student Poster
Back to main abstract page
To view the list of records returned in your search you can use your browser's
back button, or perform the same search again:
|
