Tim's journey continues...
10 February 2018.
Last report before we’re back in Chile. We are currently on the northern side of the Drake Passage, doing 12+ kts with a following sea and 25 kt winds (for the non-sailors among you, this is good), which looks like this:
And yes, the sun is out! A first (almost) for this trip.
Backing up a bit, we arrived at Palmer Station last Tuesday evening (6 Feb). This gave us a chance to get off the boat and take advantage of some of the facilities, like the hot tub with the world’s greatest view:
Wednesday was spent packing boxes of gear and samples to get them ready for shipment to Brian’s (Popp) lab at the University of Hawaii. There is an elaborate protocol for entering them into the logistics support system. Once our work was approved, we stacked the packages containing gear in a closet for safe storage (below) until we arrive in PA. Samples are kept in freezers then packed in special shipping cartons – super coolers – for immediate shipment (mostly to Brian’s lab) for subsequent analysis:
Having finished that task by lunch time, I was free to take a hike across the “back yard” and up the glacier behind the station. It was 42 oF at Palmer on Wednesday (a heat wave). The glacier was covered with slush and streams of melt water unlike anything I’d seen on previous trips. It was also visibly “dirty” from a distance, which contributed to the melting problem by decreasing albedo (the fraction of incoming solar radiation that is reflected back into the sky – that which makes snow white (and cold) and pavement dark (and hot). The dirt (that is literally what it was) was blown onto the glacier from the newly exposed, unconsolidated rocky soil exposed by the glacier’s retreat up the hill away from the station. The “dirt” included small pebbles from the size of rice grains up to peas (fierce winter winds):
These caused miniature “potholes” (the technical term among glaciologists is “cryoconites”) of melting on the glacier’s surface because they are dark and absorb solar energy, and thus warm up enough to melt the ice under them – even when covered by a foot or more of meltwater.
My first hike up this glacier was in 1989 and I was amazed to see how much it has melted since then. The “toe” has retreated up the hill by about 400 meters, and what is scarier is that the mass of ice at the crest has also decreased significantly. I could barely see the tops of the mountains that make up the south end of Anvers Island (the land on which Palmer Station sits) in 1989, while they were easily visible on Wednesday. There is a theory that the retreat of the coastal glaciers on the Antarctic Peninsula is due to warmer water from the deep ocean flowing into the coastal zone, supplying heat to melt the ice. While I’m sure this is true, the melting on the top of the ridge has to be due to a warmer atmosphere (with positive feedback from increased deposition of dust on the ice) because this ice is not in contact with the ocean – too many 42 degree days.
We left the Palmer Station at 08:00 on Thursday morning to a clear, if breezy day. Sunrise over the mountains and glacier was glorious, with clouds wrapping the tallest peaks like a cap and rolling over the lower ridges like a blanket.
We turned into the Neumeyer Channel leading to Bransfield Strait with broken clouds and sun. We realized what we’d missed coming down in the clouds and fog 6 weeks ago - we were rewarded with a completely different perspective when we could actually see what was around us:
The Neumeyer Channel is also full of wildlife: fur seals and elephant seals, but also more humpback whales and a pod of 25 or so orcas, possibly the same one we saw on the way down.
We left Antarctic behind (i.e., crossed the continental shelf break) Thursday night sometime, and entered the Drake Passage. There is no wildlife out here, other than sea birds (I saw a wandering Albatross yesterday, and lots of sooty shearwaters, storm petrels, black-backed albatross, etc.) this morning. We’ll likely see more on the Argentine Shelf and in the Straits of Magellan (Magallanic Penguins and there is an endemic dolphin), though a lot of that will be at night and because we’re back north again and it is later in the summer (yes, remember that it is summer here) it actually gets dark!!!! Maybe I’ll finally be able to see the Southern Cross!