McMurdo Sound, located in the Ross Sea, is the southernmost passable body of water in the world. Situated approximately 1,300 kilometers (810 miles) from the South Pole, it serves as a gateway for exploration and scientific endeavors on the Antarctic continent.
Geographical Setting
This icy expanse of water measures approximately 55 kilometers (34 miles) in both length and width. To its north, McMurdo Sound opens into the larger Ross Sea, while the McMurdo Ice Shelf, a segment of the Ross Ice Shelf, forms its southern boundary. Ross Island defines the eastern edge of the sound, and the Royal Society Range borders it to the west. Mount Erebus, an active volcano on Ross Island, rises to an elevation of 3,794 meters (12,448 feet), dominating the eastern landscape. On the western shores of the sound lie the McMurdo Dry Valleys, notable for their extremely low humidity and absence of snow or ice cover.
Hub of Antarctic Exploration
McMurdo Sound played a central role during the “Heroic Age of Antarctic Exploration,” a period spanning from the late 19th century to after World War I. Explorers like Robert Falcon Scott and Ernest Shackleton established bases along its shores, using it as a starting point for their expeditions towards the South Pole. Scott’s first expedition in 1901, aboard the ship Discovery, was among the initial ventures based in McMurdo Sound. Shackleton also utilized the area, notably during his 1907-1909 Nimrod Expedition, which came within 97 geographical miles of the Pole.
The sound continues its function as a logistical hub today, hosting two primary research stations on Ross Island. The United States operates McMurdo Station, the largest human settlement in Antarctica, capable of accommodating over 1,250 people. Just 2 kilometers away is New Zealand’s Scott Base. These stations serve as centers for resupply missions, with cargo ships and fuel tankers using the sound as a supply route. Aircraft also land on floating ice airstrips or ice runways near McMurdo Station during the operational season from October to December.
Unique Ecosystem and Wildlife
McMurdo Sound harbors a vibrant ecosystem adapted to its extreme cold environment. Adélie penguins build nests from pebbles on rocky shores in McMurdo Sound. These penguins eat krill, fish, and squid by diving into the ocean. Emperor penguins, the largest penguin species, also inhabit the area, with their populations facing risks from declining food availability due to climate change.
Several seal species thrive in the sound, including the Weddell seal, found near ice shelves and sea ice. These seals feed on fish, squid, and krill, diving through breathing holes in the sea ice to hunt. Crabeater seals, another common species, are seen on the pack ice. The marine life beneath the sea ice includes the Antarctic toothfish, prey for killer whales in the sound. Orcas and Antarctic minke whales are also present, with orcas hunting seals and penguins.
A Center for Scientific Research
McMurdo Sound serves as a natural laboratory, facilitating diverse scientific studies due to its unique geological features and accessible marine environment. Researchers conduct climate change studies, analyzing ice cores drilled from the continent’s ice sheets. These ice cores trap ancient atmospheric bubbles, providing data on past temperatures and greenhouse gas concentrations over hundreds of thousands of years.
Geological research focuses on features like Mount Erebus, the active volcano on Ross Island, and the distinctive McMurdo Dry Valleys. Scientists also search for meteorites in Antarctica, as these extraterrestrial rocks stand out against the vast white ice sheet. Marine biology studies observe the ecosystem under the ice, including microscopic plankton, diatoms, and various invertebrates, to understand how they adapt and function in the frozen environment. Astrophysics research also benefits from the clear, stable atmosphere, making the region suitable for telescope observations.