- Searches around Hawaii led crew of the Petrel to find the Japanese ship the Kaga
- Crew are now deploying equipment to investigate what could be another carrier
- It's believed the second Japanese carrier could be either the Akagi or the Soryu
- Battle of Midway was turning point in WWII and a key U.S. victory
- The crew are searching the vast area for other sunken warships in the coming days of which a further four remain
- Weeks of grid searches around the Northwestern Hawaiian Islands have already led the crew of the Petrel to one sunken battleship
- This week the crew is deploying equipment to investigate what could be another
Researchers discovered a second Japanese warship in the middle of the Pacific Ocean on Sunday - which sank almost 80 years ago during the Battle of Midway in the Second World War.
The battle in 1942, was a key turning point in the U.S. victory in World War II but led to the loss of six warships - four Japanese and two American. A Japanese cruiser was also destroyed.
Since then, most of the ships have remained lost at the bottom of the ocean, aside from the American carrier the USS Yorktown, which was found by an expedition in 1998, three miles below the surface.
Now new technology has allowed researchers to go deeper than ever before, and scientists have uncovered two of the downed Japanese carriers; the Kaga last week, and what appears to be either the Akagi or the Soryu on Sunday.
Vulcan Inc. director of undersea operations Rob Kraft said a review of sonar data captured Sunday shows the Akagi or Soryu resting in nearly 18,000 feet of water in the Pacific Ocean more than 1,300 miles northwest of Pearl Harbor.
The researchers used an autonomous deep sea underwater vehicle, or AUV, equipped with sonar to find the ship. The vehicle had been out overnight collecting data, and the image of a warship appeared in the first set of readings on Sunday morning.
To confirm exactly which ship they've found the crew will deploy the AUV for another eight-hour mission where it will capture high-resolution sonar images of the site. The initial readings were captures using lower resolution sonar but the high-resolution scans will allow the crew to measure the ship and confirm its identity.
The find comes on the heels of the discovery of another Japanese carrier, the Kaga, last week.
'We read about the battles, we know what happened. But when you see these wrecks on the bottom of the ocean and everything, you kind of get a feel for what the real price is for war,' said Frank Thompson, a historian with the Naval History and Heritage Command in Washington, D.C., who is onboard the Petrel. 'You see the damage these things took, and it's humbling to watch some of the video of these vessels because they're war graves.'
Sonar images of the Kaga show the bow of the heavy carrier hit the seafloor at a high rate of speed, scattering debris and leaving an impact crater that looks as if an explosion occurred in the ocean.