The first underwater archaeological investigation of the North Pacific waters off Attu in Alaska’s Aleutian Islands chain has revealed Japanese and US shipwrecks from what has become known as World War Two’s “Forgotten Battle”.
The 10-day US-Japanese expedition in the second half of July was carried out from the research vessel Norseman II, operated by Support Vessels of Alaska. It was led by maritime archaeologists from East Carolina University (ECU) under Dr Dominic Bush, who is also a research associate with Ships of Discovery.
Attu forms part of the Alaska Maritime National Wildlife Refuge, managed by the US Fish & Wildlife Service. One of the westernmost points of the US state of Alaska, it is now uninhabited.
Japanese forces captured Attu in 1942 and imprisoned its indigenous Saskinax people. This was the first and only time a foreign power has occupied US territory in North America since 1812, and American forces, supported by Canada, launched a counter-attack in May 1943 following months of aerial bombardment.
The battle ended only when the final Japanese defenders made a “banzai charge” of American infantry lines and were killed in hand-to-hand combat. The battle remains the least-studied WW2 campaign, says ECU.
A new form of sonar
The researchers were looking for any remains of aircraft, ships or submerged artefacts, using a combination of synthetic aperture sonar, a new form of hi-res imaging technology from ThayerMahan that allows small objects to be distinguished, and an ROV from World Scan Project.
The three WW2 wrecks discovered included the only two Japanese military supply ships believed to lie in US state waters. The Kotohira Maru, a 5,000-ton freighter that carried provisions, housing materials and fuel for the Japanese troops on Attu, was sunk by a US Navy weather plane on 5 January, 1943, with only two of its crew surviving.
Its remains, described as “fairly intact”, were found 1km from the ship’s last recorded position, at a depth of almost 90m.
The second shipwreck, the 3,000-ton freighter Cheribon Maru, was found draped in kelp and other marine growth in only about 10m of water close to shore, as Yasumasa Ichikawa of World Scan Project deployed a combination of its aerial and underwater drones. US bombers had sunk the vessel with the deaths of between 15 and 55 crew on Thanksgiving Day in November 1942.
The third shipwreck was the 3,500-ton cable-layer Dellwood, which was discovered 81 years to the day of its sinking. The US Army ship had struck a submerged pinnacle on 19 July, 1943, and sank later while under tow.
Sonar and ROV imagery showed it to be severely broken up at a depth of more than 30m, probably bombed deliberately to prevent it from becoming a navigational hazard.
Increased focus
The synthetic aperture sonar with its “centimetre” resolution allowed the researchers to pick out details of what they said were dozens of anchors, chains, mooring blocks and sunken buoys, as well as materials such as timbers, piping and cable used in base construction, and many sections of anti-submarine netting. No physical samples or artefacts were removed from the site.
“Overall, the project marks the beginning of what is sure to be an increased focus on the oft-forgotten Aleutian Island campaign and, by extension, Alaska’s WW2 history,” commented ECU assistant professor of history Dr Jason Raupp.
Professional archaeologist Sean Mack and Institute of American Indian Arts student Wolfgang Tutikoff, both members of descendant communities in the Aleutian Islands region, also took part of the expedition, which was jointly funded through complementary grants from the NOAA (National Oceanic & Atmospheric Administration) Ocean Exploration programme and the National Park Service’s American Battlefield Protection programme.
Also on Divernet: TEAM FINDS SUB’S MISSING BOW, WILD ALASKA, TRAGIC END TO ALASKAN RESEARCH DIVE, MYSTERY OF THE GOLDEN ORB
