plateau是什么意思？

As some countries expand operations in Antarctica, the United States maintains three year-round stations on the continent with more than 1,000 people during the southern hemisphere's summer, including those at the Amundsen-Scott station, built in 1956 at an elevation of 9,301 feet on a plateau at the South Pole.

As some countries expand operations in Antarctica, the United States maintains three year-round stations on the continent with more than 1,000 people during the southern hemisphere's summer, including those at the Amundsen-Scott station, built in 1956 at