Authorities estimate that the submersible that vanished Sunday during a dive on the wreckage of the Titanic has enough breathable air to last until Thursday under the best of circumstances as crews continue to scour the area for any sign of the vessel.

>> Read more trending news

A Canadian research vessel lost contact Sunday with the Titan, a 21-foot submersible owned by OceanGate Expeditions, about 900 miles east of Cape Cod. Five people were onboard the Titan at the time it disappeared.

Coast Guard: Canadian aircraft detects underwater noises

Update 1:09 a.m. EDT June 21: The US Coast Guard said a Canadian aircraft detected underwater noises during its search for the Titan, a 21-foot submersible that disappeared Sunday during a dive to the wreckage of the RMS Titanic, The Associated Press reported.

The noises were detected by a Canadian P-3 aircraft, which has shifted rescuers’ search efforts, according to the news organization. Those searches have still been fruitless but have continued.

Search crews continue to look for the five-person crew, as the vessel could run out of oxygen by Thursday morning, the AP reported.

Earlier, CNN reported that an internal U.S. government memo said crews heard banging at 30-minute intervals.

— Bob D’Angelo, Cox Media Group National Content Desk

Submersible has about 40 hours of air left, officials estimate

Update 1:30 p.m. June 20: Coast Guard Capt. Jamie Frederick estimated that the Titan had about 40 hours of breathable air left on Tuesday as efforts to find the submersible continue.

The Titan had an estimated 96 hours of breathable air when it vanished on Sunday. Search efforts have so far uncovered no signs of the missing vessel.

“This is a very complex search and the unified team is working around the clock to bring all available assets and expertise to bear as quickly as possible in an effort to solve this very complex problem,” Frederick said.

Search efforts ‘have not yielded any results,’ USCG says

Update 1:25 p.m. EDT June 20: Searches by air and sea have found no sign of the Titan, Coast Guard Capt. Jamie Frederick said at a news conference Tuesday.

“Our crews are working around the clock to ensure that we are doing everything possible to locate the Titan and the five crew members,” he said.

The Coast Guard is coordinating search and rescue efforts with other agencies, including the U.S. Navy, the Canadian Armed Forces and the Canadian Coast Guard.

“To date, those search efforts have not yielded any results,” Frederick said.

Original report: Authorities have searched more than 10,000 square miles for signs of a submersible that vanished Sunday during a trip to see the wreckage of the Titanic.

The submersible, owned by OceanGate Expeditions, had five people onboard when it went into the water about 900 miles east of Cape Cod in Massachusetts, the U.S. Coast Guard said. By sea and air, U.S. and Canadian officials have searched an area bigger than the state of Vermont.

“We’re working very closely at this point to make sure that we’re doing everything that we can do to locate the submersible and rescue those on board,” Coast Guard Rear Adm. John Mauger said Monday at a news conference. He noted at the time that officials believed the submersible had between 70 to 96 hours of emergency capabilities onboard.

The Coast Guard is expected to share an update on the search effort at a news conference on Tuesday afternoon.

Officials said the Polar Prince, a Canadian research vessel, lost contact with OceanGate’s submersible during a dive on Sunday morning. On Monday night, officials with OceanGate Expeditions said they were “exploring and mobilizing all options to bring the crew back safely.”

“Our entire focus is on the crewmembers in the submersible and their families,” the company said. “We are deeply thankful for the extensive assistance we have received from several government agencies and deep sea companies in our efforts to reestablish contact with the submersible. We are working toward the safe return of the crewmembers.”

The Titanic was a British passenger liner and the largest ship of its time. It hit an iceberg and sank in the Atlantic Ocean during its maiden voyage in 1912, killing more than 1,500 of the roughly 2,220 people onboard.

The wreckage of the ship sits about 380 nautical miles south of Newfoundland in Canada at a depth of about 12,800 feet.

ExpandAutoplay

Image 1 of 32

Titanic FILE PHOTO: On September 1, 1985, underwater explorer Robert Ballard located the world's most famous shipwreck. The Titanic lay largely intact at a depth of 12,000 feet off the coast of St. John's, Newfoundland. Using a small submersible craft, Ballard explored the wreck in 1986, taking a series of spectacular and haunting pictures and giving the world its first glimpse of the legendary ship in 73 years. (Ralph White/Getty Images)