Complete the following sentence: Ernest Shackleton's southern party (Shackleton, Adams, Marshal, Wild) of the
1908 Nimrod expedition were the first humans to cross the Ice Shelf during its failed attempt to reach the South Pole. Both Roald Amundsen and Scott crossed the shelf to reach the Pole in 1911.<unk> Both Roald Amundsen and Scott crossed the shelf to reach the Pole in 1911. Amundsen wrote: "Along its outer edge the Barrier shows a even, flat surface; but here, inside the bay, the conditions were entirely different. Even from the deck of the "Fram" we were able to observe great disturbances of the surface in every direction; huge ridges with hollows between them extended on all sides. The greatest elevation lay to the south in the form of a lofty, arched ridge, which we took to be about high on the horizon. <unk> <unk> <unk>