After some initial seal related frustrations we were treated with a spectacular Antarctic day. It's a little difficult to make it in this photo, but at one point we got a beautiful double "ice-bow". The source of the ice-bow is the same as a rainbow, except that ice crystals not water droplets are causing the refraction. You can make out the large red splotch where the seal left one of his or her many markings on around our old pool.
I said it was good to have a Plan C as well. Sunday’s normally a day off at McMurdo but after breakfast we headed out to check on our not yet complete frost flower pool and to see if we could get a little further on removing all the ice from it. Unfortunately it was immediately apparent on arriving at our site that we’d have to abandon Plan B. The seal that we had seen nosing around the day prior had clearly claimed our pool as a hang out spot, with a neatly maintained seal hole in one corner of our pool. That alone wasn’t a huge problem but seals are pretty messy animals. Like other aquatic creatures they aren’t too picky about when and where they relieve themselves. Seal holes are usually pretty well marked with fishy pink excrement and this one was no exception. In fact this particular seal seems to have gone above and beyond the norm in this case. From a microbiological standpoint the pool is irrevocably contaminated even if we could get rid of the seal, which we can’t.
Our intrepid volunteer for the day Sandwich (neither Shelly or I got the backstory on her nickname) gets ready to drill some holes in our new pool.
It was however, a beautiful Antarctic day and we didn’t want to waste it. We quickly hatched Plan C, which was to dig a pit about half the thickness of the ice and then drill a couple of small holes all the way to the bottom. This shouldn’t look that attractive to a seal as a breathing hole and should give us some frost flowers. The downside is that this sort of pool isn’t going to circulate as well as a pool with an open bottom. I don’t know exactly what this would mean for the marine microbial community that might ultimately end up in the frost flowers, but it might not exactly represent a natural situation. But then again it might be good enough. If we are unable to sample natural frost flowers a few such pits (if they work) might get us the samples we need.
And here's our new seal-free pool starting to freeze over.
Fortunately the chance to get some natural frost flowers has never looked so good! Dan’s long scout with Ryan, another McMurdo staffer on Saturday was pretty successful. Maneuvering around cracks and thin ice they were able to get to Cape Royds. Enroute they past some small leads chock full of frost flowers. Even better from Cape Royds they were able to see the ice edge, with large expanses of young ice leading to open water. Although they didn’t get out on this young ice it has a whitish look that suggests it is covered with frost flowers. With luck we’ll be on our way up there early tomorrow, pending approval from the McMurdo Station managers and good weather…
First glimpse of an Antarctic frost flower, from Dan and Ryan's trip to Cape Royds on Saturday. Photo: Ryan Wallace.
Why do you need to create frost flowers? Why can’t you use the ice or frost that is already there?
We would much prefer to use frost flowers that have formed naturally, but they are very difficult to get to. Frost flowers are very abundant when sea ice is forming but getting safely out to an area where this is happening is quite difficult. The ice is thin and newly formed ice floes are prone to drifting out to sea. We have ways of dealing with these issues but we haven’t yet had all of our plans approved by the managers at McMurdo Station. In the meantime we can do some things by inducing frost flowers to form in a place that we can reach. Although our artificial frost flower plot is surrounded by sea ice the bacteria that end up in them will be quite different from the bacteria in the surrounding ice, in part because the environment of the flowers is much different (colder, more salty, more light).
oh they look so beautiful!!!!