All Systems Go and Mid-season Changeover

There is much progress to report, and lots of exciting science happening at Law Dome. First, all of our systems have now been set up and tested. Sharon and Jose have excavated a beautiful 2m-deep trench, which is now the home of the 4-inch drill, the bandsaw and the freezer.

Tanner and Grant drilling in the trench. Photo: Vas

Tanner and Grant promptly set up the 4” drill, which is what will be used to recover the deep (up to ≈240m) preindustrial ice and the air it contains. Andrew set up the ANSTO bandsaw, which produces fantastic straight cuts on our ice cores.

Andrew testing the ANSTO bandsaw with some 4” core. Photo: Vas

The bandsaw will be used for taking a sliver from one of the 4” cores. This continuous sliver of ice will be analyzed for isotopes of H2O and allow us to determine the ages of the ice layers as well as a more accurate history of snow accumulation rate at the site.

The large ice melter (which we’re using to extract lots of old air from the ice, for measurements of carbon – 14 of carbon monoxide) has been performing extremely well, much better than in all of our tests back home in the lab. We have now completed 5 melt-extractions of air from the large BID cores. These samples will help us to understand how much of the carbon – 14 in our samples is due to production by cosmic rays directly in the ice.

We also did a first test of the large melter system with 4” ice cores, to confirm that the drilling and handling process for these smaller cores is equally clean (it is) and works well (it does).

Vas and Peter with 4” cores stored in a side cave. Photo: David E

Vas pulling the clean sled with 4” cores toward the melter. Photo: David E

Loading ice chips into melter bottom (needed for melting to start quickly). Photo: David E

4” core getting its final cleaning prior to the melt. Photo: David E

The large ice melter full of 4” cores. Photo: Vas

It is hard to believe, but the field season is already over for some of us. Vas, David Etheridge, Richard and Andrew left Law Dome 2 days ago for Casey Station, arriving almost exactly at the same time as Ed and David Thornton, who came via a Basler flight from McMurdo station.

The Challenger tractor at a rest stop on our way back to Casey. Photo: Vas

The team is down to 5 up on the Dome (Sharon, Jose, Tanner, Grant and Peter) – they are currently short-staffed, but are doing their best to keep some of the work going. Fingers crossed that the weather holds and Ed and David Thornton are able to get up to the field site quickly!

-Vas

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