A site for deep ice coring in West Antarctica: results from aerogeophysical surveys and thermo-kinematic modeling

Abstract

The U.S. Science Plan for Deep Ice Coring in West Antarctica calls for two ice cores to be collected. the first of these cores, from Siple Dome, was completed during the 1997/98 field season. the second core is to be collected from a site near the divide that separates ice flowing to the Ross Sea and to the Amundsen Sea.Using high-resolution, grid-based aerogeophysical surveys of the Ross/Amundsen ice-divide region, we identify seven candidate sites and assess their suitability for deep coring. We apply ice-flow and temperature calculations to predict time-scales and annual-layer resolution, and to assess the potential for basal melting for several selected sites. We conclude that basal melting is likely for sites with very thick ice, as was observed at the Byrd core site. Nevertheless, these sites are most attractive for coring since they promise recovery of a long climate record with comparatively high time resolution during the last glacial period.

A new bipolar ice core record of volcanism from WAIS Divide and NEEM and implications for climate forcing of the last 2000 years

“…The drilling was finished in 2011 to a depth of 3405 m. Here we discuss results of the upper 579 m of the main ice core ("WDC06A"). A welldefined ice flow regime [Morse, Blankenship, Waddington, and Neumann, 2002] and modern accumulation rates of 200 AE 34 kg m -2 a -1 [Banta, McConnell, Frey, Bales, and Taylor, 2008] make this site a unique archive for highresolution chemical analysis. A shallow ice core "WDC05Q" drilled at WAIS Divide in 2005 was used to validate results during the overlap period of 1521 and 2005 C.E.…”

Does δ<sup>18</sup>O of O<sub>2</sub> record meridional shifts in tropical rainfall?

“…The 3404 m long WD ice core (79.48 • S, 112.11 • W) was drilled at an elevation of 1766 m between 2007 and 2011. Present mean-annual air temperature and accumulation rate at the WD ice core site are −30 • C and 22 cm ice equivalent per year (Banta et al, 2008;Morse et al, 2002). The youngest 31.2 kyr (2850 m) was dated by annual-layer counting (Sigl et al, 2016), while the oldest portion of the core (up to ∼ 68 ka) was dated by CH 4 synchronization to the Greenland NGRIP ice core, scaled linearly to match the timing of abrupt events recorded in U/Th-dated speleothem records (Buizert et al, 2015b (Dole, 1935;Morita, 1935) and has a modern-day value of ∼ 23.88 ‰ .…”

Shallow-source aeromagnetic anomalies observed over the West Antarctic Ice Sheet compared with coincident bed topography from radar ice sounding—new evidence for glacial “removal” of subglacially erupted late Cenozoic rift-related volcanic edifices

“…From December 1991 to January 1997 we acquired an orthogonal gridded aeromagnetic survey at a 5-km line spacing (Blankenship et al, 1993(Blankenship et al, , 2000Behrendt et al, 1994Behrendt et al, , 1998Behrendt et al, , 2002aMorse et al, 2001) over central West Antarctica (Fig. 2) combined with radar ice sounding (Fig.…”

“…Therefore, high heat flow is probable beneath the thick ice of the WAIS. See the discussion of likely basal melting by Morse et al (2001). The WAIS and the late Cenozoic volcanic activity in the West Antarctic rift system have been coeval since at least Miocene time, although the area has been deglaciated at times during this period as recently as 400 ka (e.g., Scherer, 1991;Scherer et al, 1998).…”