After a few weeks of preparation to get the hot water drill ready, and complete some run-throughs of deploying SCINI we’re moving off of the sea ice and out onto the ice shelf. The first step in this process was utilizing two huge tractors to pull the drill and all our gear out into the field in what is known as a traverse. This slow haul took a large bite out of our first day in the field. Once we arrived we started to set up camp while the drillers began prepping the drill for the next day’s goal of boring through the shelf.
These huge tents are 8 ft. x 20 ft. which gives us a substantial amount of warm covered area to work with. This site is only a 30 minute ride away from McMurdo station via snowmobile, so currently we are just making the drive out and back in the morning and evening so we don’t have to rough it until we have to. The next field sites will have much longer commute times (~1.5 hours on snowmobile and 3-4 in the piston bullys) so we’ll be making use of the tents to save time and fuel in the near future. Additionally 3 hours on snowmobiles wears on you pretty heavily as the cold is extremely draining.
These windswept patches of blue ice allow you to see the uniqueness of the ice shelf. The completely freshwater floating mass slid off of the continent miles away from here and has been slowly pushed out over the sound. The top layer is riddled with cracks from the immense stresses this dynamic geographical entity undergoes.
After a full days work of setting up camp we headed back to McMurdo to eat and sleep well before rising early again for the first day of drilling.
The morning came quickly. We rolled out of bed, ate a generous amount of breakfast, geared up and headed out to the site. The weather was not quite so idillic, and the cold, cloudy ride out was brisk. Nevertheless, we arrived at camp and got to work. The agenda; finish setting up the insides of the tents, set up a GPS station to locate our camp and also measure the rise and fall of the ice shelf with the tides, and get a hole drilled for the submersibles.
Unlike a typical drill with a bit, this drill uses hot water to melt a hole through the ice. This gives us the freedom to make the hole any size we want by merely varying the water pressure. The drill ejects hot water from one hose and recovers it with another, and reheats it to use what we melt to continue the drilling. The Achilles heel of the drill is the cracks and fractures in the ice because the hot water seeps into these gaps if one intersects the hole. Then snow must be melted to drill past the crack and continue the hole, however this is time consuming because water is lost until the crack is bypasses. Unfortunately this occurred only a few feet into this hole and progress was slowed to a near standstill. While the drillers continued to work past the crack, the rest of us decided to take a little hike over to the Pegasus wreck, which is about a mile away from our camp.
In 1970 the Pegasus crash landed in near zero visibility white out. Everyone in the crash survived, and the plane remains out on the I’ve shelf to this day. The Pegasus ice shelf runway is named after the miracle landing.
When we returned to camp the drill was back in action and we kept melting through until dinner. We headed back into camp after about 40 meters of ice was melted. The plan for tomorrow is to finish the hole and get SCINI down under the shelf, which here means 60 meters of ice. We’re hopeful we’ll see some interesting ice structures beneath the shelf’s icy veil that could illuminate its morphology, as well as recover water samples to understand the water chemistry in this bizarre environment that allows organisms to thrive here.
Earlier in the week I trekked up Observation Hill, a small mound next to McMurdo Station, that provides some incredible views of the surrounding scenery, including Mount Erebus, Mount Terror, the sea ice, the ice shelf, and the Transantarctic range.
This next week should be an exciting, and likely tiring, one. With ice shelf operations up and running we’ll be doing SCINI dives daily until we break down camp and move to another location to do it all over again. Additionally Icefin soon will make it’s maiden voyage in the safety of the sea ice before also making the journey out to our field camp to take the plunge through the borehole and start exploring the sub-ice world with unprecedented detail (imagery, salinity, temperature, and sonar).
Cheers! – The SIMPLE Crew