10 December, 1999

Running the Hot Finger

One component of the McMurdo Dry Valleys Long Term Ecological Research project is to monitor the type and amount of sediment that filters down through the water column at Lake Hoare. For the last few years, the lake team has set two sediment traps under the ice by drilling holes, setting the traps on a long line and noting their positions, then letting the lake freeze the holes closed. Craig, Renee and I began the process of retrieving the traps this morning. First, we had to cut through the ice. Since Craig knew exactly where he set the traps last year, we could pinpoint the locations we needed to drill. We used a drill head with a four-inch bit to cut holes through fifteen feet of ice. We had to be careful not to cut the lines or the traps would be gone forever.

Craig has been using the ATV to haul the "hotsie" and generator over the ice to the hole. Both sit on metal trays to prevent the skis from melting into the ice and freezing in. The hotsie holds a large container of glycol, which flows through a "hot finger" similar to one I described in an earlier entry.

The hot finger is stored in the white plastic cylinder. The black hose is attached to it and is long enough to drop the hot finger to the bottom of the hole. Renee is about to put fuel from the green canisters into the generator, and then the hotsie will force glycol to run through the hose.

This type of hot finger is quite substantial-more so than the paper clip style. Metal tubing is coiled around the outside, providing a large surface area for the hot glycol to pass through.

As we lower the hot finger into the hole, we hang on to a rope line and the hose. The bamboo pole in the background will be laid across the ice in a cross to keep the whole thing from pulling on the hotsie.

The hot finger is almost to the bottom of the hole. Once the bamboo cross is set, it will take at least ten hours to melt out the holes enough to pull the sediment traps out.