Antarctic Sound and Brown Bluff
We awoke to yet another beautiful morning, with vistas of the Antarctic continent to starboard and giant icebergs ahead of us. The ship was to spend most of the day in Antarctic Sound (named for the Swedish ship Antarctic used by Otto Nordenskjöld during the Swedish Antarctic Expedition of 1901-1904). By mid morning, we found ourselves in brilliant, cloudless conditions, although a bit windy, and took the time to check out a magnificent tabular berg close-up with the ship (Figure A). The huge chunk of ice most likely emanated from the collapse of the Larsen B Ice shelf about ten years ago and eventually grounded here where it will stay until it breaks up into smaller pieces and drifts off. Just for fun, Expedition Leader Tim Soper measured it. The berg was sitting on the bottom in 170 meters depth and towered 30 meters above the surface. It was 0.9 kilometer in length and had a surface area of about 500,000 square meters. Some quick calculations came up with a volume of roughly 100 million cubic meters, or 100 million metric tons. This is all the more impressive remembering that the original ice shelf, including this chunk of ice, formed from the simple accumulation of snow over an immense period of time.
Many more icebergs and tabular bergs (and bergy bits and growlers and ice floes) were passed as we made our way along the tip of the Antarctic Peninsula (sometimes called Trinity Peninsula). In the early afternoon, Captain Kruess worked the ship around some pack ice, where we saw lots of seals resting on the ice and a pod of killer whales obviously in search of seals resting on the ice, and he got us in close to a spectacular geological formation called Brown Bluff (Figure B). This is where we decided to make a landing. Brown Bluff is a continental site consisting of a long beach backed by a spectacular, rust-colored cliff rising to 2,225 feet (675m) above sea level. Its appearance is not unlike the sandstone mesas of the American west, although this is actually a volcanic formation that has been partially eroded away exposing the interior of the structure. Most of the eroded material has washed into the sea, but there is considerable debris still to be seen on a raised level extending seaward from the base of the cliff to the steep, sloping beach. This huge volcano stands against the peninsular ice cap that is forced to flow around it, thereby providing a protected area for breeding penguins (both Adélies and gentoos), as well as several other species of birds, including snow petrels, pintado petrels, skuas, and kelp gulls. Not surprisingly, the Adélie penguins had already departed the region by this late date, but plenty of gentoo penguins were still in evidence. It was fun walking along the shoreline, watching gentoo fledglings cavort in the shallows learning how to swim and feel comfortable in the water. Others were still being cared for by their parents, but we all knew this would soon come to an end as the breeding season finishes up and all the fledglings would be on their own.
The place abounded with non-breeding male fur seals, making themselves at home among the boulders. These animals were too small to compete with the bigger breeding bulls this past breeding season on distant South Georgia, but many of them probably had hopes of gaining size and weight over the winter and trying out next season for their own breeding territories. Some of them were seen play fighting in preparation of things yet to come.
The waters around Brown Bluff proved to be an excellent place for Zodiac cruises among the floating ice and along the glacial face. Some people were fortunate to witness a large calving at an ice cave close-up. We all continued enjoying the icebergs throughout the evening as the ship completed her transit of Antarctic Sound and headed out toward the South Shetland Archipelago for more adventures.
