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team because the ice shelf is the largest in Antarctica, and it holds back the flow of the ice sheet upstream. One of the primary interests of the researchers is to learn the history of the Ross Ice Shelf and the climate of the region over the last glacial-interglacial transition. Roosevelt Island is also located at the terminal end of the West Antarctic Ice Sheet, which once ex- tended over the top of the site, but has retreated since the end of the last ice age. So, the team is hopeful new spatial information about the climate in West Antarctica will be found with an ice core from the site. It took nearly three years for the team to build the camp, select the drill site, and install the drill. The goal is to drill an ice core to a depth of nearly 3000 feet. To do this, the drill must be hollow because the goal is to retrieve core samples and not to destructively drill through the ice sheet. As the drill head carves out the ice cores, the team must keep the borehole open by collecting the ice cuttings. The ice cuttings look like shaved ice because an ester-based drilling fluid must be used to lubricate the drilling process and fill the void caused by the coring. Once the ice core is retrieved, it must be stored and shipped at a low temper- ature. The average yearly temperature for a low elevation site like Roosevelt Island is -9ºF (-23ºC). That’s pretty cold. So, it shouldn’t be very hard to keep the ice core at a low enough temperature, right? Well, actually it’s quite a bit more complicated than one would think. One of the primary aspects the team will look for during analysis of the ice is measuring the ancient samples of atmospheric gases like carbon dioxide and methane. The problem is these gases will start to diffuse when the cores get warmer than about -1ºF (-18ºC), and during the summer, the temperature can get close to 32ºF (0ºC). So, the team will keep the ice cores at an appropriate -9ºF (-23ºC) by storing them in a freezer located in a snow cave nine feet below the surface, which will have ducts plumbed into it to circulate air through the unit. Finally, the ice core will be flown out of Antarctica on a plane with all the heat aboard turned off, while the plane flies higher than normal. This keeps the cores cold enough until they get to the landing destination, where they will be unloaded and stored in a mobile freezer on a big sled. The sled will tow the cores back to Scott Base where a final freezer awaits to ship them across the ocean to New Zealand. Once home in New Zealand, the team will analyze the core samples to see what the ancient ice will reveal. Open the Doorway to all the Event Photos! To see all the photos from this event, go to: www.worldwidedrillingresource. info/gallery/2017/MGWA2017, or just click here. Feel free to download at will and print the photo(s) of your choice. Compliments of WorldWide Drilling Resource ® . Photos are copyrighted and released for personal use only - no commercial use permitted. It’s All About the Ice cont’d from page 36. 48 JUNE 2017 WorldWide Drilling Resource ®