#McMurdo #DryValleys #Antarctica

Today started early, really early. In fact it had already gone midnight by the time we went to bed after our successful landing at Cape Royds on Ross Island for our visit to Shackleton’s hut. However at quarter to 4 it was time to get up again for a pre-breakfast excursion to Scott’s hut at Cape Evans, further down the coast on Ross Island. The swell was quiet large and the wind was almost 40 knots, but we felt we could do it. We started to launch boats, but the ship was drifting and unable to hold its position due to the wind, so unfortunately we had to call off the operative.

We then recovered the only lowered boat and fell asleep again, as the ship sailed back across McMurdo Sound to the entrance of the Dry Valleys. Unfortunately the sea ice situation had deteriorated further and we were only able to get within in 6 miles of the entrance to the valleys. The wind was still blowing 40 knots and the Trans-Antarctic Mountains were still draped in cloud. It was all very depressing and looking very doubtful.

We waited and waited, then the cloud showed signs that it was lifting, however the wind was still 40 knots. Expedition Leader Don, and chief helicopter pilot Marcello decided they would do an exploratory flight into the Dry Valleys to see what the wind conditions were like up there. The pilot very skilfully lifted off the ship in the windy conditions and headed out across the ice towards the lifting cloud of the Dry Valleys.

After 45 minutes they returned. We were all eating in the dining room and Don announced that it was a GO! The wind was still high at the ship, but inside the valleys there was no wind and it was do-able.

As the ship’s Geologist, I was lucky enough to be selected to fly in on the first helicopter to prepare the landing site for the passengers. It was an experience I will never forget. First we flew over ice floes and newly forming sea ice, with sleeping seals near to the shore line. Then we flew up over the land – dry land with no snow even though we were at nearly 78 degrees south. As we flew over the bare ground, I could see frost wedges caused by freezing and thawing of the permafrost. Then we saw the first glaciers: the Wales glacier coming in from the left and later the amazing piedmont of the Commonwealth glacier and our destination the Canada Glacier, coming in from the right.

The Dry Valleys are free of ice because the Tran-Antarctic Mountains are so high. Ice from the East Antarctic Ice Sheet does not spill over into them to flow down these valleys. In addition to this the area is incredibly dry. There is very little snowfall and this snow cannot accumulate as a glacier. Any snow that does occur, often sublimes straight to water vapour or is blown out by the extreme catabatic winds that can rage down the valleys. As chance would have it there was some snow there on our visit day. The previous day’s storm had left a thin layer on the higher ground and on some of the boulders but it was quickly ablating away.

The helicopters landed at the foot of the Canada glacier, with forms an elephant’s foot or piedmont glacier as it emerges from it restrictive Canada Valley into the main dry Taylor Valley. In front of the glacier were a few ice blocks produced by an extremely low rate of calving. In the hottest days of the year these will melt and flow into nearby Lake Fryxell, which today was completely frozen. The interior of this lake is always frozen but on the hottest days of the year a thin moat of water will form around its edges.

On the valley floor, at our landing site, there were three mummified seals. These unfortunate beasts had once made the wrong call, and crawled the wrong direction to find the sea. Eventually they died, but because the conditions were so cold they have been perfectly preserved. One of these seals has been dated at 2000 years old. Also on the valley floor was a large assortment of different rocks types, but all were either igneous or metamorphic. These rocks show that the Taylor Glacier has at some stage flowed down through this valley because these are all the rocks types that outcrop higher up in the Taylor Valley.

As the day went on helicopters and groups of passengers came and went. Eventually the last passengers had arrived and then it was time to go on another incredible helicopter ride over the glaciers, and the sea ice back to the ship. Visiting the Dry Valleys was a dream come true for me, and today was my best ever day working as a guide on an expedition ship.

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