This morning, National Geographic Explorer dropped anchor off Gourdin Island, a small chip of volcanic rock near Prime Head, the northernmost point of the Antarctic Peninsula. This region of the peninsula was first charted by the great French explorer Dumont d’Urville on the second voyage of his ship, Astrolabe. D’Urville named the little island after his ensign, James Gourdin.
Gourdin Island is best known as one of the few places where all three species of brush-tailed penguins—Adélie, chinstrap, and gentoo—nest together. We saw mostly chinstraps, but there were still a few Adélies and gentoos about. At this point in the season, young penguins are entering the sea for the first time, learning to swim, and preparing to spend their first winter in the Southern Ocean. With so many inexperienced birds in the water, this is also prime time for leopard seals—there were quite a few of these magnificent predators in the water between the island and the little rocky islets just off shore. Several of the big seals quickly approached the boats and some of us had great views of them, twisting and turning gracefully beside and under the Zodiacs. But the seals proved to be a bit too aggressive for our comfort; we left that area to explore away from the island in deeper water.
About half a mile off the north coast of Gourdin Island, a rock with a prominent pinnacle attracted our attention. It proved to be a very nice outcropping of columnar basalt, the summit pillar formed from a single isolated column. While circumnavigating it in our Zodiacs, we found that on the seaward side of the rock the basalt faces were coated with beautiful patterns of rime ice, which made an intriguing subject for photography. The rock itself was also quite intriguing: The mainland of the peninsula in this region is mostly ancient sedimentary rocks, but the basalt we were looking at was clearly volcanic in origin. It seemed to be more closely related to the rocks of the South Shetland Islands, nearly 100 miles to the north on the other side of the Bransfield Strait. This observation led to a lively discussion of the geologic history of the Antarctic Peninsula and the creation of all the spectacular landforms we’ve encountered while exploring this incredible polar wilderness.
