Days this week were filled with testing seismic, GPS, and radar equipment, sorting camping supplies, and meeting with various departments at McMurdo for trainings and briefings. Most of our seismic instruments for this season are out in the field, where we need to retrieve them, but we do have 24 3-component Magseis Fairfield Z-Land 5-Hz nodes to deploy for a short time (~30 days) this season as part of a small seismic study to further characterize the environment (especially the top 10-20 meters) of Thwaites Glacier. The nodes were shipped south over several months, so we set up a mobile laptop node server with 3 charging and data offload ports in our McMurdo office to charge up their batteries after the long shipment. We will use the same setup to download data from the nodes after we deploy them and record data in the field.
We also had our skidoo traverse and linked travel training as well as practicing glacier linked travel on foot. We drove six snowmobiles out of McMurdo for about an hour and discussed good practices for long distance snowmobile travel and how to stay warm while snowmobiling. We all tried out various helmets as well to test what would be comfortable for the field season. We lucked out on the weather again with another beautiful, sunny day at Ross Island and the ice shelf. Some of us had never ridden a snowmobile before, so it was a great opportunity to learn about operation, managing gear, and fueling snowmobiles. We towed a wooden Nansen sled with our three survival bags and our HF radio to test in the field (again). The solid frame of the Nansen is particularly helpful behind the lead skidoo, as it provides stability over an edge in the event the lead skidoo falls into a crevasse. We practiced traveling in groups of 3 linked skidoos, which required traveling very slowly to keep the skidoos the appropriate distance apart.
After a brief lunch and rest break, we linked together as a hiking rope team to practice glacier travel on foot. If one person falls into a crevasse, the others will self arrest in the snow surface with their ice axes to stop the person from falling very far beneath the snow surface. Then the team will work to help the fallen person out of the crevasse. These are important skills for working or hiking safely on glaciers.
Once we arrive at our field site at the Eastern Shear Margin of Thwaites Glacier, one of our first tasks will be to travel all of the routes between our seismometers, GPS, and radar instruments with a ground penetrating radar (GPR) as a linked skidoo team to check the terrane for any hazards such as crevasses beneath the snow surface. We will flag the routes and stick to those routes for the duration of the field work. As a bonus, the GPR data can also be used for science applications to understand the structures in the top 20+ meters of snow. Since shear margins are the location where ice goes from moving on the glacier to not moving off the edge of the glacier, they sometimes have crevasses, but the past several seasons at the Eastern Shear Margin of Thwaites have suggested that the area is not crevassed in the near surface. We are always excited when we have the chance to use geophysics to look beneath the surface of the glacier!
Thank you so much to our incredible Field Safety Coordinators, Mike and Kirah, for being amazing instructors and organizing our field safety trainings!
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