This is a detail from one of the regularly updated maps that researchers in Antarctica use when they want to leave McMurdo Station and travel across the continent's sea ice. It shows the well-traveled routes across McMurdo Sound, ice thickness measurements taken at various points along the road, and hazards like large cracks in the ice.

Towards the north end of the Sound, you can see an island labeled, "Inaccessible Island". I asked Henry Kaiser — a musician and filmmaker who has spent the last decade working with scientists on the frozen continent — about why that island was inaccessible. After all, I didn't see any major cracks or hazards around it. Seems like you could traverse the ice to the island just fine.

Turns out, I was misunderstanding. Inaccessible isn't a designation. Inaccessible is the island's official name. Even though it's not. Inaccessible, I mean. Named by Robert Scott, it's part of a chain of islands that all represent the remains of an ancient volcanic crater. The name apparently comes from the fact that Inaccessible Island is incredibly steep, so while you can reach it, getting onto the damn thing seems to be a lot harder.

Inaccessible Island in McMurdo Sound is not to be confused with the Inaccessible Island that is located in the south Atlantic about halfway between South America and Africa; nor with the Inaccessible Islands, an entire group of islands located between the tip of South America and tip of the Antarctic peninsula; nor with Inexpressible Island, an Antarctic island where part of Scott's crew on his second expedition was forced to spend the winter of 1912 living in a cave and eating penguins.

Read about Inaccessible Island (the one in McMurdo Sound) in the report of Robert Scott's first expedition to Antarctica, published in 1907.