Lori Dopplick, age 10, of St. Louis, Mo., for her question:

WHAT IS THE ROSS ICE SHELF?

Antarctica, the area around the South Pole, was the last continent to be explored by man. Men first set foot on the continent when John Davis, an American seal hunter, sent his crew ashore on Feb. 7, 1821. At the time they did not know they had landed on the mainland.

A British explorer named James Clark Ross arrived in Antarctica in 1841. He discovered the Ross Sea and the Ross Ice Shelf. The ice shelf is actually a vast glacier that covers the entire southern half of the Ross Sea.

Ross also sighted the Transantarctic Mountains along the coast and named the region Victoria Lane in honor of Queen Victoria.

Norwegian Arctic explorer Roald Amundsen crossed both the Ross Sea and the Ross Ice Shelf in 1911 when he became the first person to reach the South Pole.