Seismic popsicle

The reason for me returning to Davis Station this season was to help retrieve the instruments we left out on the ice last season and download all of the data they have hopefully been recording. Among other things we left three broadband seismometers. These were to be installed in plastic tubes with a concrete base, to keep the instruments level and water tight. When we arrived on Station last year we discovered the tubes were a little too short. The guys in the workshop did an amazing job of extending the tubes and we installed three of a potential four of them. The instruments have been installed in the ice for just over 10 months and I for one was a bit apprehensive about the state they would be in. After the low light recce when we discovered that there was basically no snow to contend with this year we thought the job could be relatively straight forward. We were also trying to be realistic and so packed many tools of extraction to aid the process. Landing at the first site it looked promising, initially we started to cut out the ice just downstream of the solar panel and logger box. We soon realised that the cables connecting the logger to the seismometer were running off to the side and using the steam drill we followed them and found out first tube! Amazingly it was still upright and intact. I rather excitedly prised off the lid to remove the cables and instrument only to find the tube full of ice… It was also frozen solid into the ice and took a lot of careful melting, chipping and sawing to get it out. After about 6 hours we finally managed to get out the first ever seismic popsicle. If we thought the tubes were heavy when we put them in it was nothing compared to being full of ice! Interestingly the data logger was still collecting data until mid August, the middle of the Antarctic winter, giving me a glimmer of hope that the instrument might return to life once defrosted. For now all we could do is take it back to station and try to melt the ice.

Happy to find the first site looking intact
With a bit of steaming we found the first tube upright!
Excitedly prised off the lid to find….ice
A big hole and much pushing and pulling later the worlds first seismic popsicle was extracted
About six hours and lots of tools of extraction later
Melting the popsicle in the brewery

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