Friday was a long day for the divers, the SCINI crew, and the entire ICE AGED team.
Julie and I helped our Reedrill expert, L.T., drill four more huge holes for our SCUBA divers.
L.T. pulls the Reedrill with a big tractor
While he lowered the gigantic drill, we shoveled the snow out of the way so the water, which is under pressure under the ice, could escape out a designated path rather than flood the entire area. It's quite exciting when we hit water and see it gushing out.
Julie shovels a path so the seawater can escape
After shoveling the snow, we scoop out the remaining ice chunks and drill little holes with a big hand-held drill for black flags to indicate danger to others. "Watch out. Don't fall in this hole!" We scooped out our three other holes so now we have seven holes in the ice for our divers and SCINI.
Tina chipping the hole while a Weddell seal yearling sunbathes
We only have 2 tomatoes and 1 "fish hut" covering the holes so we'll be busy the next few days breaking and scooping out the ice layer that forms each morning and using the Tucker to move our huts from hole to hole. It was good exercise and with the clear, beautiful day that we had today, along with a launch of two giant balloons from the French scientists on base and a visit by a sunbathing seal, it was wonderful to be outside.
Where is this balloon going and what are they measuring with it?
While we were on our mission, the divers jumped in the water again and later a group of us packed food for our upcoming field camp out on the ice at a location called New Harbor. The engineers were also busy refining SCINI and taking her out on another dive.
David works on software for SCINI, DJ works on mechanical issues, and Bob supervises and helps with everything
I've accompanied them on several of their missions so far and have been very impressed by the knowledge and trouble-shooting abilities of the engineers.
Watching SCINI fly underwater is an amazing experience! I was able to see the seafloor more than 120 feet below me from the comforts of a warm hut.
The Tucker takes the team and SCINI out to the dive hut on the sea ice.
Though SCINI is somewhat simple for an ROV, she is actually pretty
complicated.
What do you think the biggest challenges to flying her would be?
What tools do the engineers have to help them?
DJ helps guide SCINI into the dive hole in the hut
Watching the engineers fly her underneath the ice, I realized that knowing which way she was pointed was one of their hardest tasks. The thick layer of ice means they can't just see watch her fly, and the proximity to the South Pole means that the magnetic field angle is too high for them to accurately use a traditional compass.
The lights on SCINI illuminate the 15-foot layer of ice that she flies under. The metal pole going down the hole has a navigation transducer that uses underwater acoustics to relay positioning information.
Fortunately, they have several tools to help them. They have a navigation system which uses underwater acoustics to tell the engineers where SCINI is in relation to the dive hole and in which direction she is headed once she is moving. They also have sensors that indicate "tilt" and "roll" to show numerically and graphically which way she is facing. Tilt indicates if her nose is up or down; roll indicates if she's rolled over onto her left side or her right side.
Unfortunately, the engineers cannot control the underwater terrain. If the seafloor were flat it would be easier, but it has canyons, hills, mountains, and walls, just like landscape. They do have lights as well as two cameras, one on the front of SCINI and one looking down, but it's hard to accurately judge the underwater terrain when you only have limited vision. Two lasers on SCINI set 10 cm apart help with general sizing, but in the end, DJ and Bob explained that it's like driving your car by looking through a hole in the floor. (Do NOT try that at home!)
5 monitors display a wealth of information: the left monitor shows navigation, the middle monitors show the downward looking camera's view, the top right shows what the front camera sees, and the bottom right one has the tilt, roll, navigational and instrumentation data
One of the things they're working on right now is integrating the tracking postioning onto a real world subsea topographic map. With this they would have something similiar to the bird's eye view on the GPS in your cars. They would be able to see SCINI as a dot on an actual map of the seafloor on their computer monitors. Once they have that up and working it will be much easier for them to visit previously mapped features and to find Paul's old experiments.
David flies SCINI, while DJ works with the navigation settings, and Bob and Paul watch the seafloor
Control of SCINI is also a challenge. Fist, the tether is a complication as it adds either weight or buoyancy to their underwater robot. The tether is required as it relays information and electricity to and from the robot in the water. However, the tether can add a significant amount of weight to their robot if it is not properly counteracted by the addition of small floats. Thus, the engineers have added little pieces of syntactic foam as floats though they had to calculate exactly how much floatation to provide as a heavy tether would point the nose up and a light tether would point the nose down - potentially flying her either continually up or down into the seafloor.
White flotation devices keep the green tether buoyant
Furthermore, the underwater current can be strong enough to push SCINI and the tether around. While this underwater submarine is only about 4 feet 8 inches long and 7 inches in diameter, if you add even 500 feet of tether, it's significant enough to get pushed around on the seafloor. DJ explained to me that it's similar to trying to fly a hot dog on a string underwater.
David and DJ pull a dripping SCINI out after she flew in the water for 8 hours
Between the hog dog analogy and the driving through a hole in the floorboard visualization, it's a wonder how the engineers manage to control SCINI, much less use her to take pictures, do video transects, or look for and retrieve Paul's old experiments in an environment as harsh as Antarctica.
SCINI illuminates the dive hole as a seal wonders what's going on