Field and CPL Updates

2011 Core Processing Line

August 5, 2011
Update provided by Peter Neff
project update image
Annual layer picks at 3060 meters depth, WAIS Divide ice core. Black triangles indicate annual layer picks. The annual layers are resolvable by both DC- and AC-ECM. Annual layers are still ~3 cm thick at this depth. The figure shows interpretation of annual layers across a break in data (3060.35, from a drilling run break) as well as occasional noise due to irregular electrode/ice contact (3060.07). AC data are scaled to match DC data. Credit/Data: T.J. Fudge

After eight weeks of ice core processing here at the National Ice Core Lab, one week has started to blend into the next. In the tedium of seeing meter after meter of ice pass through the processing line, we sometimes lose track of the magnitude of just what we are seeing every day. Last Tuesday was a day for us to wake up and remember just how impressive this WAIS Divide ice core is. In that one day, we processed ice that was deeper than the GRIP ice core from Greenland (3029 m), then deeper than the Dome Fuji core in East Antarctica (3035 m), and finally deeper than the previous "deepest U.S.-drilled ice core," GISP2 from Greenland (3053.4 m).

We ended the week at a depth of 3140 meters, with just less than 200 meters to go this summer. Despite the unavoidable fatigue that sets in over such a long stint in the lab, some of us are still excited to catch the first clues as to what sort of record we have in the bottom ice from WAIS Divide. T.J. Fudge (UW) has again provided us with a science tidbit, which shows surprisingly thick annual layers deep in the core, detected by electrical conductivity measurements. We are watching vigilantly for any unusual features in the ice, as disturbance by ice flow or other subglacial processes is all but unavoidable around these depths in the ice sheet. Stay tuned for updates on deeper ice in the coming weeks!

Peter Neff
WAIS Divide SCO Representative, 2011 CPL