The WAISCORES initiative calls for two ice cores to be collected from West Antarctica: an “ice dynamics” core and a “paleoclimate” core.  The first of these was  collected from Siple Dome its analysis  is underway.  Taylor and others (2000) put forth a  WAISCORES Science and Implementation Plan as a blueprint for accomplishing the second of these cores.  Consistent with these objectives, we have been evaluating  the Ross Sea / Amundsen Sea ice flow divide region (Figure 1) of West Antarctica for suitable for deep coring sites.  An aerogeophysical survey of the West Antarctic interior conducted by UTIG provide the basis for this evaluation.  We have identified several candidate sites that characterize  the region.  The WAISCORES Plan presented two of these sites spanning the range of ice thickness likely to be encountered.  Here we present a more detailed analysis of all seven sites, their locations and physical parameters are given in Table 1.  These sites are labeled A-G in each of the aerogeophysical maps, along with 25 meter surface elevation contours for reference. Figures 2, 4 and 8 show primary aerogeophysical survey observations from laser altimetry, radar  sounding and magnetics.  Bed elevations, Figure 5, were derived by subtraction of  surface elevation and ice thickness.  Figure 6 and 7 present radar stratigraphy (layering) information interpreted as modern mean ice accumulation rate and relative timescale discrepancy at depth. Figure 3 presents detailed temperature, timescale and layer thickness calculations for the two sites, E and G, that correspond with those of the WAISCORES Plan.   Timescale and layer thickness results for each of the sites are summarized in Table 2.  With the thick ice and low surface elevations characteristic of this ice sheet, the potential for basal melting (and loss of the older portions of the environmental record) is of particular concern.  We present temperature calculations for an assumed time-varying climate history and two values of geothermal flux in Table 3.  Finally, Table 4 from the WAISCORE Plan summarizes core recovery times for two of the candidates site.
 
 

Table 1: Site locations and Parameters.	Figure 1: Location map.	Figure 2: Surface elevation map.
Figure 3: Temperature, layer thickness and timescale plots	Figure 4: Ice thickness map.	Figure 5: Bed elevation map.
Table 2: Timescale and layer thickness summary.	Figure 6: Accumulation rate map.	Figure 7: ~10 ka Isochron topology.
Table 3: Potential for basal melting.	Figure 8: Magnetic field anomaly map.	Figure 9: Divide survey coverage map.
Table 4: Core recovery time.

References:

Behrendt, J.C., D.D. Blankenship and R.E. Bell, Aeromagnetic evidence for a volcanic caldera(?) complex beneath the divide of the West Antarctic ice sheet. Geophysical Research Letters, 25(23), 4385-4388, 1998.

Sweeney, R, C.A. Finn, D.D. Blankensip, R.E. Bell and J.C. Behrendt. Central West Antarctica aeromagnetic data: A web site for distribution of data and maps. Open File Report No. 99-0420, 15 pp.  U.S. Geological Survey, Denver, Colorado, 1999.

Taylor and others, WAISCORES: A science and implementation plan for ice dynamics, climate and cryobiology studies in West Antarctica, prepared for the U.S. Ice Core Working Group, June, 2000.
 

Acknowledgment:

Special thanks to UTIG students George Tsoflias, Jennifer Doebbler and Allison Mielke for assistance with data reduction. This work was supported by NSF-OPP 9615251.