Interesting but more and more brittle ice

Sarah sure knows how to spoil the crew - lots of delicious dishes day after day

It became a day of excitement at the ice core processing table. After we passed some 1.1 m of glacial ice from the Younger Dryas period yesterday, we anticipated to encounter some 2 to 4 m ice of the milder Bølling and Allerød periods today. We indeed got ice from those periods, but that section appears to be around 10 m of thick in the core. Later we dived into ice from the last glacial maximum that is characterized by a very low ECM signal. Finally, we encountered two warming events that we believe are two Dansgaard-Oeschger events, but this needs to be verified by the water isotopic climate record.

The ice is indeed turning more and more brittle. Most of the drilled ice cores are 1.8 m long sections with no or just a few internal breaks. But as the core is being handled or just left on the processing table, larger pieces of core tend to break off, and internal cracks form. The cutting with the circular saw does not introduce additional breaks and we are quite satisfied with the saw, but still it is impossible to avoid the unfortunate core cracking this close to the brittle zone. Fortunately, we got some high clouds coming in and outdoor temperatures dropped somewhat, so it was possible to continue drilling and processing until dinner time. The logging depth is 544.94 m.

Weather: Starting out with blue sky, we later got complete overcast with high clouds and light snow fall. Wind has been turning 270 deg. anti-clockwise starting out in NW and now in NE. Temperatures -5°C to -7°C. Pressure has been dropping over the last days.

Relaxing moment with old news