Field and CPL Updates
Dear WAIS Divide Enthusiast,
Lots of progress this week.
Core recovery hummed along this week with recovery rates of ~ 27m/day. Our depth on Sunday was 3,224 m, which is about 74 ky BP. By the time you get this we will be deeper. The sampling for a low-resolution 18O record results in a clear 3 cm wide window that allows us to look into the core, and we are carefully inspecting each core as we near the bed. A volcanic ash band showed up with ~ 1 cm clumps of ash instead of an even distribution. Nelia Dunbar says this is likely caused by the tephra being deposited during the summer that resulted in some melting due to the decrease in albedo. A second tephra band had some wave like features with an amplitude of a few mm.
Our last day of drilling has been extended five days to January 29th. Getting five extra days at the end of the season is a big deal, and we thank our camp manager Paulene Roberts for working out the details and Julie Palais for laying the groundwork early in the season. We hope to reach our depth goal for the season (3,330 m) on Friday the 28th. This is as deep as we can go and be confident we will not connect with a possible basal water system. Downhole measurements next season will provide a more accurate measurement of the thickness of the ice under the borehole and will likely allow us to safely drill another ~40 m without connecting to the basal water system. (In contrast, the Russians are currently trying to penetrate into Lake Vostok and might do so this season.)
We start packing the camp this week, and will not have email after Thursday morning.I accompanied another shipment of ice from WAIS Divide to McMurdo. The temperatures were in the -10 to -15 C range, and the crew was very responsive. We are cooling the aircraft for at least two hours before it arrives at WAIS Divide. This is the only way to assure that the equipment and crew are able to hold acceptable temperatures. It is more important to accompany the flight to WAIS Divide to check the aircraft before the ice is loaded, than it is to accompany the ice to McMurdo when not much can be done to change the outcome of the mission. I will be returning to WAIS Divide on Wednesday and staying until after we pull the last core.
Heidi Roop did another PolarTREC broadcast. Matt Stan and Jeremy Polk have been working on their short videos and the early cuts are looking good.
There is a lot of energy pushing this effort along. You know this when you get off the plane and are greeted by a tribe of dancing people dressed as a unicorn, gorilla(s), penguin, bear, raccoon, banana, and I can't remember what else. Our last five days of coring will be a blur.
Below are the two SITREPs from Giff and Jay that provide all of the details.