Matt and Anthony’s first field day –
After a weeks worth of persistent nasty Condition 2 weather the clouds have dispersed, the sun is shining, and the wind is, well, at least not as bad as it was. Spirits are high with good weather abound and the opportunity to gear up and drive some snowmobiles out onto the sea ice, drill some holes, and get a look at whats down there. This week has been filled with test runs on the sea ice, prepping everyone for SCINI’s deployment through the ice shelf next week. Our first SCINI run with the engineering crew present went swimmingly and everyone seamlessly jumped into the routine.
This being a test run, the motions were pretty much identical to our previous post. However, the scenery on this day made for a few choice photo opportunities. Including a Weddell seal basking on the snow near us.
As the sun sunk lower in the sky droves of helicopters began returning from carrying cargo out to the McMurdo dry valleys, another scientific hotspot near the station.
As always even the skyline provided a scenic backdrop to our day at ‘the office’.
Mystery Peak –
Later in the week we split ranks and Matt, Mick, and Anthony stayed back to assemble Icefin, while Catherine, Britney, and I headed out to a ‘sea mound’ with Stacy Kim’s crew. The sea mound is a drastic rise in the ocean floor, this one hidden under 4 meters of sea ice in the McMurdo Sound. This particular sea mound is particularly intriguing as it houses a completely different benthic biosphere than the surrounding seafloor. We sent SCINI down to document the two different ecosystems (actual SCINI pictures forthcoming, I promise!!). Although the skies were clear, the wind made the hour long snowmobile ride out, as well as the field work a little taxing. The distance from the station did, however, provide us with a brilliant view of Erebus and put us in our most humblingly remote location yet.
In addition to SCINI’s launch, we helped Stacy’s group deploy a long term time lapse camera system on the top of the sea mound, which will continue to take photographs of the subsurface world for the rest of the season before it is pulled back up.
The Trans-Antarctic Range, Mount Erebus, and Erebus Glacier –
The next day Britney, Matt, and I spent three hours after dinner getting further acquainted with the snowmobiles as we took a long haul expedition to do some reconnoissance for the field sites we will be traversing to starting next week. These six locations were picked to explore a potentially diverse array of underwater dynamics and ecosystems. To get there we have to travel far across the ice shelf, which has few flagged roads and zero less natural features, so we wanted to begin to get a feel for how we’ll go about traveling from the base to our field camps. Our plan is to take marked roads as far as we can and then diverge off of them and utilize GPS’s to go the last leg to our sites. We spent this evening planning routes and finding our turnoffs.
Dive #3 : Sea Ice and Ice Shelf Transition –
The next day Matt, Catherine, Britney and I, along with Stacy’s group, headed out onto the white expanse one again. This time our destination was one along the transition between the yearly melting sea ice and the permanent ice shelf. This location is of interest because the ice shelf is an extension of a glacier, a gargantuan slab of fresh water ice that slides off the land and floats atop the ocean, making it drastically different from the sea ice. Being permanent makes even the edge of the shelf up to tens of meters thick, which is extremely difficult to drill through. However at the transition, we have the opportunity to launch SCINI through the much thinner sea ice and then swim under the shelf to see the difference in the environment under the fresh water shelf.
One thing that we’re particularly interested in is how the freezing and melting of fresh water from the ice shelf affects the underside of both the shelf itself and the sea ice, dynamically as well as biologically. One side effect is the increase of frazil and brash ice. When warm currents melt the bottom of the shelf the freshwater melt flows out towards the sea ice. When it reaches the saltier sea ice it refreezes in platelets and discs that sit in a slush under the ice instead of just freezing to the underside of the ice. While for us this, up to 20 ft. thick, slush means lots of ladling it out of the hole to get SCINI down through it, this water logged salt slurpee provides a safe, nutrient rich, haven for algae and other microorganisms which in turn feed other creatures under the ice. This is incredible, as this type of ecosystem extends far under the ice shelf to places completely devoid of light, and brings into question whether the same type of frigid, but bustling, habitats could exist elsewhere in our solar system (and throughout the universe).
Although this day was particularly ideal, sunny and no wind at all, being outside in the cold all day takes its toll and you can’t get too bogged down in being totally serious and sciencey all the time. Luckily we’ve got a crew that knows how to keep morale high.
On the agenda:
-Tank testing Icefin
-Prepping for movement out to far off field camps
-Catherine and I teach the rest of the crew how to cross country ski!!
(look forward to pictures from ALL of these events)
Cheers! – The SIMPLE Crew