After plans for an Arctic (North Pole) expedition were undercut by competing claims of success, Japanese army reserve officer Nobu Shirase redirected his ambition toward Antarctica. This decision placed Japan into the international "race" era of polar exploration, alongside larger European-led expeditions.
With limited official support, Shirase relied on private fundraising and influential supporters to finance a voyage south. The expedition prepared to sail in a small converted fishing vessel, Kainan Maru, which would shape what was realistically possible in Antarctica.
The expedition sailed from Tokyo aboard Kainan Maru, beginning Japan’s first Antarctic venture. The late-season departure increased the risk that sea ice and worsening weather would block access to the continent before winter set in.
After a difficult voyage, Kainan Maru arrived in Wellington. Local reactions were mixed, with some observers doubting the expedition’s readiness because of the small ship and the lateness of the season.
By March 1911, the expedition reached Antarctic waters but found access blocked by thickening sea ice as the austral (Southern Hemisphere) winter approached. Unable to land safely, Shirase chose to withdraw rather than risk losing the ship and crew.
Kainan Maru sheltered in Sydney through the Antarctic winter, giving the team time to repair, resupply, and plan a second attempt. This pause was essential: the ship and crew needed to be ready to sail south early in the next austral summer window.
With the sailing season returning, Kainan Maru left Sydney on its second attempt toward Antarctica. The expedition now focused on achievable exploration and travel goals rather than insisting on a South Pole victory.
After reaching the Ross Sea region, the Japanese crew saw the Great Ice Barrier (now commonly called the Ross Ice Shelf), a floating wall of ice at the edge of the Antarctic interior. This marked their arrival in the main operating area used by several Heroic Age expeditions.
The expedition found what looked like a landing site and sent a party up onto the ice to evaluate travel conditions. They reported many hidden crevasses (deep cracks in the ice), making long-distance surface travel dangerous from that spot, so the ship moved on.
Near the Bay of Whales, the Japanese crew discovered Fram, the Norwegian ship used by Roald Amundsen’s South Pole expedition. The meeting highlighted how crowded and competitive Antarctic exploration had become in 1911–1912, even in remote regions.
After landing a small team with dogs on the Ross Ice Shelf, Shirase launched a “Dash Patrol” to travel as far south as possible. Severe weather initially slowed them, but the party continued despite cold, wind, and injuries among the dogs.
While the Dash Patrol traveled over the ice shelf, Kainan Maru carried another team to King Edward VII Land. The Japanese made a successful landing from the sea and explored inland until crevasses and rough ice blocked further progress.
With supplies running low, the sledging party reached its furthest south point at 80°05′S and turned back. They raised the Japanese flag and named the area Yamato Yukihara (“Japanese Snow Plain”), then made a rapid return to their base camp.
After recovering the Dash Patrol and reuniting the expedition’s two operating groups, Kainan Maru left the Antarctic region. The decision to depart reflected the expedition’s limited time window before worsening ice and weather could trap the small ship.
Kainan Maru arrived back in Wellington after leaving Antarctica. This stop allowed rest and resupply before the final leg home, and it also served as an early point where the expedition’s results could begin to be communicated internationally.
The expedition reached Japan in June 1912, marking the successful completion of the country’s first Antarctic exploration voyage. Although it did not reach the South Pole, it demonstrated long-distance polar travel by a non-European nation and returned without loss of life, leaving a legacy later recognized in place names and historical reassessments.
Japanese Antarctic Expedition (Nobu Shirase, 1910–1912)