December 4, 2014

We have now been on the glacier for over 2 weeks, and the work is going in full swing. Weather has been kind (knock on wood), with much less wind so far than last season.

Once again, we are lucky to have a fantastic team – the most important single factor that determines the success or failure of a season. Returning Taylor Glacier veterans include Ed Brook (OSU faculty and co-PI on the project), Thomas Bauska (OSU post-doc), Mike Jayred (IDDO driller), Michael Dyonisius (UR PhD student) and myself. New to the glacier are Kathy Schroeder (our camp manager), Andy Menking (OSU PhD student), Rachael Rhodes (OSU postdoc), Sarah Shackleton (SIO PhD student) and Jake Ward (recent UR graduate). Sarah and Jake are completely new to polar fieldwork, and both have adjusted extremely well to life on the glacier with all its particulars, such as sleeping in the cold and 24-hr daylight.

 

Jayred (in back) brings the drill sonde up to the surface as Jake prepares to help.

Jayred (in back) brings the drill sonde up to the surface as Jake prepares to help.

Michael (wearing Tyvek suit) crawls inside the large ice melter to install the bubbler manifold.

Michael (wearing Tyvek suit) crawls inside the large ice melter to install the bubbler manifold.

Vas trims the ends of large ice cores prior to loading in the ice melter.

Vas trims the ends of large ice cores prior to loading in the ice melter.

Overall, progress has been good. We were off to a good start with the BID drill, our smaller ice drill system (Sidewinder), as well as making methane measurements on small ice samples for reconnaissance purposes with the gas chromatograph system (GC). The large ice melter system we use to collect samples for carbon-14 analyses of ancient methane was slower to get going because of a persistent leak. The large ice melter has to be extremely leak tight and hold a good vacuum in order to avoid contaminating our ancient air samples with modern air that contains a higher level of carbon-14 and methane. After extensive testing, the leak was finally traced to a poor seal on our viewport, and both the o-ring and the viewport glass were replaced, which solved the problem. Work on the leaks and the test run pushed us into some very long hours, which included I think a new record for this system – a 20-hr work day! We have by now collected our first full sample, extracting approximately 12,500 year old air from about 1100 kg of ice and also collected a full procedural test sample, which helps us to determine the effects of any non-sample (“extraneous”) carbon that is added during the many stages of sample processing and preparation.

Ed, Thomas and Rachael removing a heating element from the spare GC.

Ed, Thomas and Rachael removing a heating element from the spare GC.

Ed and Thomas cutting the ice sticks for the continuous melter system on a bandsaw.

Ed and Thomas cutting the ice sticks for the continuous melter system on a bandsaw.

Stick of ice being melted on a clean gold-plated warm plate.

Stick of ice being melted on a clean gold-plated warm plate.

Ed and Rachael have worked stoically to get the continuous methane measurement system going. This is a new system for us at Taylor Glacier, and is designed to allow for methane measurements on a stick cut from the ice core. The stick is melted slowly on a warm plate, and part of the meltwater (and with it the ancient air) is siphoned off through a small orifice in the middle of the warm plate. The gases are then separated from the water and the methane concentration is analyzed using a laser spectrometer. When this system works well, it can produce a very high resolution methane record extremely fast, and would be a very powerful tool for our methane-based studies of the ice layer stratigraphy and identification of ice that we want to sample for carbon-14 analyses. Unfortunately, some of the heating elements used in the warm plate were damaged during the initial system setup. Ed and Rachael have been extremely resourceful in trying to solve this problem and were able to adapt the warm plate to take a different-size heating element from the spare GC system. The system is now working well and producing excellent-quality continuous data for methane concentration.

Andy with the methane GC system

Andy with the methane GC system

The methane GC system has been working very well from the start and Andy has produced excellent data on ice samples that Thomas and Sarah recovered with the Sidewinder system. So far these measurements have allowed us to very clearly identify the ≈18,000 year old ice section that contains the very start of the atmospheric methane increase from the low concentrations of the Last Glacial Maximum. The GC data have also identified the large rapid atmospheric methane oscillation (decline and subsequent increase) that happened at around 8,200 years ago, when a large burst of water from the melting North American ice sheet slowed down the warm water circulation in the North Atlantic and caused widespread cooling. Both of these time intervals contain important clues to how the natural atmospheric methane cycle works and are targets for our large-volume carbon-14 sampling.

Kathy has been working tirelessly on setting up and maintaining our camp, and keeping us all fueled with her amazing cooking. Thanksgiving dinner (which we had last Sunday) was outstanding!

-Vas

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