Eighty years after first being deployed to detect Nazi submarines during World War II, sonobuoys are helping to find the missing Titanic explorer.
underwater sonar device hear knocking In the area titan submersible Disappeared as search is still nearby for ships that disappeared from radar shipwreck on Sunday.
Live updates from the Titanic sub-search
Marine Corps operations specialist Mike Welham told Sky News that voices could be heard every 30 minutes, indicating someone had “taken over” the sub and was “putting out a tap” in the hope of being detected —maybe know how to find out. Sonobuoys have developed into a key tool in the search for people missing at sea.
What exactly are sonobuoys?
In short, they are designed to use sonar to locate underwater objects.
The devices come in two parts and are packaged in a cylindrical tank until they drop into the water.
Once dropped from aircraft in formation, they deploy in just a few minutes. The video below shows them up and running.
Once deployed, inflatables with radio transmitters are placed on the surface, while equipment for detecting noise is strung along wires and lowered below the surface.
Any signals received are relayed from transmitters on the ground to the aircraft.
They are an important part of the naval search team’s arsenal because radio and GPS signals cannot travel through water.
How do sonobuoys pick up sound?
Sonobuoys use two forms of detection to identify underwater noise.
Passive detection means that they listen to the sounds produced by the vessel such as propellers and machinery.
This is a cheaper and simpler type of sonobuoy that uses underwater microphones called hydrophones.
Instead, active detection sends out a sonar “ping” that bounces off the surface of a sub like Titan, then uses the returning echoes to map the water and locate any objects.
Instead of hydrophones, they use sensors, which function like antennas.
Dr Rob Rattle, a marine geophysicist with the British Antarctic Survey, said both the hydrophones and the sensors convert sound signals into electrical signals, “which can then be analyzed using signal processing software”.
During this analysis, it is possible to determine which direction the signal is coming from.
He added: “If the source is not at the bottom of the sea, then a ‘ghost’ arrival reflecting off the bottom of the sea may also be detected, which would indicate the altitude at which the source is located.”
The U.S. Navy uses sonobuoys to search for the missing USS ARA San Juan in 2017
How were they deployed before?
Sonobuoys are designed as strictly military hardware.
They were first used to detect German submarines during World War II.
They were also heavily used during the Cold War to track nuclear submarines around the world.
The devices are still used by countries’ armed forces, from the US Navy to the UK Ministry of Defense, but their use has diversified to include search and rescue operations.
They have been used before in the hunt for black boxes Missing Malaysia Airlines Flight 370 After it disappeared over the Indian Ocean, and was looking for An Argentine submarine that went missing in 2017.
read more:
Why Finding Missing Submarines Is So Difficult
What we know so far about the missing submersible
Sonobuoys are also being used to find Malaysia Airlines flight MH370 in the Indian Ocean
How are they used to find titans?
They were thrown into the waters off Newfoundland, Canada by a P-3 aircraft.
From there, they descend to the desired depth – up to about 1,500 feet. For context, the wreck of the Titanic lies approximately 12,000 feet below the surface of the ocean.
While officials have said investigations into the impact sound they received were negative, experts insist sonobuoys remain critical to narrowing the search.
How the missing sub-saga unfolded
“The ocean floor is huge and the water depth is huge,” said Mr Wareham, who likened finding submersibles to finding coins on a football field.
Noises from Titan should be distinguished from the North Atlantic environment, and the decision to investigate the explosions suggests that officials believe there is something wrong with them.
Forensic Geoscience reader Dr Jamie Pringle said it was “unlikely” that they came from a surface ship propeller or another submarine.
“Noise travels a long way in water, so it’s both good news and bad news,” he said.
“You still need three static buoys to be able to triangulate the sound source to determine the location.”