We saw Emperor and Adelie penguins at Beaufort Island but no open water anywhere, leading to the question where are these birds feeding? This isn't an idle thought; the colony at nearby Cape Crozier failed to successfully rear any chicks on years when the configuration of icebergs calving from the Ross Ice Shelf trapped sea ice near the colony, blocking access to open water and food.
The last few days have been fast and furious as we try to wrap up our sampling program. We fly back to New Zealand in exactly one week which means that time is quickly running out! Fortunately we’re getting close to complete. We lucked out on Monday with superb weather for our flight to Beaufort Island. A large network of leads often forms around Beaufort at the interface between the freely drifting pack ice and the ice loosely anchored to the island. The most recent satellite images that we could obtain, from late September, looked promising. Unfortunately when reached Beaufort we couldn’t find open water or young sea ice anywhere. The thinnest ice that we could find was over 50 cm thick, suggesting that the leads had frozen over soon after the satellite images were taken.
Pull very short ice cores from young sea ice after sampling frost flowers. You can see one of the short cores in the lower right of the image.
This was very disappointing. With time running short we decided to head to nearby Lewis Bay on the north side of Ross Island where we sampled on Saturday. The ice and frost flowers in Lewis Bay are pretty old, but a lot younger than what we found off Beaufort. Enroute to Lewis Bay however we stumbled across a very large, recently frozen lead with ice only 13 cm thick. Perfect! This is thick enough to work on with little risk of breaking through but thin enough that the lead must have been open just days before. Every surface on the lead was coated with frost flowers. They looked a little droopy in the heat (-15 C and sunny!), but good enough for us…
It takes a while to find solid landing sites next to thin sea ice like this; the pilots need a solid 30 inches to land the helicopter. By the time we found a spot and got sorted out for sampling it was getting late in the day, we are grateful for the helicopter crew’s willingness to stay out a little longer to get the job done!
So close yet so far away. Looking down at Taylor Glacier and Lake Bonney at the point of turnaround. Visibility was good but the winds were too high for a safe landing on slick glacial ice.
Back home there was little time to rest. We had to re-sterilize our equipment and get turned around quickly for a trip to Taylor Glacier the next day. The weather didn’t look too promising from the McMurdo helicopter pad but we decided go ahead and try for it. We made it across the Sound and all the way up the Taylor Valley before high winds forced us to turn around. It was heartbreaking to look down on our sampling site and not be able to reach it, but the pilots here are an experienced bunch and we have to trust their judgment. Conditions continued to deteriorate as we crossed McMurdo Sound back to the Station. We were within 10 minutes of the helo pad when visibility and a rapidly descending ceiling forced us to turn back around and return to the west side of the Sound. Having just been chased east by bad weather it was a little like being caught in a vise.
There are worse places to be stuck. Waiting out the weather at Marble Point.
This sort of thing happens fairly frequently however, and as a result there’s a way out. A small fueling station and field camp is maintained at a site called Marble Point, at the foot of the Wilson-Piedemont Glacier. Three people staff the fueling station and they’re always ready for visitors. The crew of another helicopter, also trapped on the west side of McMurdo Sound, was already there. We sat down for a large, delicious hot lunch, cookies, and lots of coffee before deciding what to do.
Marble Point is very close to our old sampling site on the Wilson-Piedemont Glacier so we decided to take the opportunity to collect fresh snow from nearby. This is a sample we were planning to collect later in the week. It didn’t take too long (it was probably the easiest sample we’ve collected on the whole trip), so we enjoyed the scenery while we waited for the helicopter to take us back to Marble Point for more waiting. And wait we did. Just as we were reconciling ourselves to spending the night at Marble Point (which with their cozy bunkhouse is not a bad thing) a brief weather window opened around McMurdo. We hurriedly loaded the helicopter and went for it. It was an interesting flight. A full ground blizzard was blowing at the sea ice surface as we flew into McMurdo, it looked like a vast river of snow moving underneath. At altitude the helicopter was riding on waves of air, it felt rather like being on a small boat in ocean swells. The motion was never alarming, just a constant reminder of the energy on the other side of the thin plexiglas windows.
Shortly after we landed the weather window closed. Our flight to Taylor was rescheduled today and canceled. We are now 0 for 3 on Taylor Glacier. Tomorrow we will try to visit our Tent Island site which should be easier than reaching a glacier deep in a windy valley. That leaves Friday and Saturday for renewed attempts at Taylor. After that we need to close up shop and get ready to head home!
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