Read the passage below:
In January 1911, Norwegian explorer Roald Amundsen established Framheim, a primary base camp located on the Ross Ice Shelf in Antarctica. During February and March, the expedition members focused their efforts on laying supply depots at key latitudes along their designated route to store essential provisions. After wintering at Framheim, five men equipped with four sledges pulled by fifty-two dogs officially began their final journey toward the pole on October 19, 1911. Traversing treacherous glaciers and ice fields, the team successfully arrived at the South Pole on December 14, 1911, where they planted the Norwegian flag.
Based on the explicit details provided in the passage, place the following events from Amundsen's expedition in chronological order from earliest to latest.
- 1Establishing the Framheim base camp on the Ross Ice Shelf
- 2Laying supply depots along the designated polar route
- 3Beginning the final polar journey with sledges and dogs
- 4Planting the Norwegian flag at the South Pole