Category Archives: 2014 (12/11) Brinicles Under the Sea Ice
Dec 11, 2014
When I was at McMurdo Station, I had the opportunity to visit the ‘Observation Tube’, which is a narrow tube drilled through the sea ice surrounding McMurdo Sound that leads to a small, windowed seat where you can take in the scenery beneath the sea ice. I took my GoPro camera into the tube with me and was able to hear the sounds of a few different seals making their surreal, ‘sci-fi’ sounding squeaks under the ocean, as well as get my first view of brinicles.
Brinicles are concentrated columns where extra-salted seawater sinks to the ocean floor. When ice freezes, the purer water freezes first and pushes saltier water away from the ice structure. As more and more fresh water freezes, the liquid remaining behind gets increasingly concentrated (as well as increasingly cold-while-not-frozen), and eventually this salty brine, which is denser than the surrounding fresh water, sinks towards the bottom. Since the brine is still very cold, though, the low temperature causes nearby freshwater to freeze around it as it sinks, creating a tunnel of freshwater ice surrounding the column of deepening salty brine. The brinicles were distinctly visible as ‘ice tubes’ underneath the sea ice in the video, and it was beautiful to sit in the Observation Tube and take in the 360 degree view beneath the ocean surface.
Check out the video below! I included a little video section of the hike towards the Ob-Tube across the ice simply to show a little more of what it looks like to hike around near McMurdo Station, but the dialogue between my friends and I isn’t important, it’s just part of my experience taking a trip under the ice. (*To read the text within the video, make sure your youtube settings are set to a quality of at least 320p. Most faster internet connection speeds will use HD quality (720p) anyway, but if the text is blurry, check this setting.)
The BBC series ‘Frozen Planet’ also has an amazing segment where they filmed an extreme time-lapse of the formation of brinicles under the ice, part of which is available here-