Is mystery underwater sound the crash of Flight 370?
David Molko, Mike M. Ahlers and Rene Marsh, CNN
Updated
7:37 AM EDT, Wed June 4, 2014
Story highlights
An Australian university releases an audio clip and other information
Researchers have studied records from underwater listening devices
A sound that was picked up is not near the current search area for MH370
The academics say it could be related to the missing plane, or just a natural event
(CNN) —
Australian researchers released an audio recording Wednesday of an underwater sound that they say could possibly be related to the final moments of missing Malaysia Airlines Flight 370.
It’s a long shot, but researchers at Curtin University near Perth, Australia, have been studying records from underwater listening devices, including those meant to monitor for signs of underwater nuclear explosions, in an effort to help find the missing plane.
“One signal has been detected on several receivers that could be related to the crash,” said Alec Duncan with the university’s Centre for Marine Science and Technology (CMST).
Researchers have been analyzing the very low frequency sound for weeks to see if it was “the impact of the aircraft on the water or the implosion of parts of the aircraft as it sank,” Duncan said. “But (the source of the noise) is just as likely to be a natural event.”
Photos: The search for MH370
Two years after Malaysia Airlines Flight 370 went missing, a relative of one of the passengers burns incense in Beijing on March 8, 2016. Flight 370 vanished on March 8, 2014, as it flew from Kuala Lumpur, Malaysia, to Beijing. There were 239 people on board.
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Visual China Group/Getty Images
Photos: The search for MH370
On July 29, police carry a piece of debris on Reunion Island, a French territory in the Indian Ocean. A week later, authorities confirmed that the debris was from the missing flight.
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Lucas Marie/AP
Photos: The search for MH370
Staff members with the Australian Transport Safety Bureau examine a piece of aircraft debris at their laboratory in Canberra, Australia, on July 20. The flap was found in June by residents on Pemba Island off the coast of Tanzania, and officials had said it was highly likely to have come from Flight 370. Experts at the Australian Transport Safety Bureau, which is heading up the search for the plane, confirmed that the part was indeed from the missing aircraft.
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ATSB/AP
Photos: The search for MH370
In late February, American tourist Blaine Gibson found a piece of plane debris off Mozambique, a discovery that renewed hope of solving the mystery of the missing flight. The piece measured 35 inches by 22 inches. A U.S. official said it was likely the wreckage came from a Boeing 777, which MH370 was.
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Blaine Gibson
Photos: The search for MH370
Relatives of the flight's passengers console each other outside the Malaysia Airlines office in Subang, Malaysia, on February 12, 2015. Protesters had demanded that the airline withdraw the statement that all 239 people aboard the plane were dead.
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MANAN VATSYAYANA/AFP/Getty Images
Photos: The search for MH370
A police officer watches a couple cry outside the airline's office building in Beijing after officials refused to meet with them on June 11, 2014. The couple's son was on the plane.
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Andy Wong/AP
Photos: The search for MH370
Members of the media scramble to speak with Azharuddin Abdul Rahman, director general of Malaysia's Civil Aviation Department, at a hotel in Kuala Lumpur, Malaysia, on May 27, 2014. Data from communications between satellites and the missing flight was released the day before, more than two months after relatives of passengers said they requested it be made public.
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MOHD RASFAN/AFP/Getty Images
Photos: The search for MH370
Operators aboard the Australian ship Ocean Shield move Bluefin-21, the U.S. Navy's autonomous underwater vehicle, into position to search for the jet on April 14, 2014.
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Peter D. Blair/U.S. Navy/UPI/LANDOV
Photos: The search for MH370
A member of the Royal New Zealand Air Force looks out of a window while searching for debris off the coast of western Australia on April 13, 2014.
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Greg Wood/Pool/AP
Photos: The search for MH370
The HMS Echo, a vessel with the British Roya; Navy, moves through the waters of the southern Indian Ocean on April 12, 2014.
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British Ministry of Defence
Photos: The search for MH370
A Royal Australian Air Force AP-3C Orion, on a mission to drop sonar buoys to assist in the search, flies past the Australian vessel Ocean Shield on April 9, 2014.
A relative of a missing passenger cries at a vigil in Beijing on April 8, 2014.
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STRinger/AFP/Getty Images
Photos: The search for MH370
Australian Defense Force divers scan the water for debris in the southern Indian Ocean on April 7, 2014.
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Lt. Ryan Davis/Australian Defense Force/AP
Photos: The search for MH370
A towed pinger locator is readied to be deployed off the deck of the Australian vessel Ocean Shield on April 7, 2014.
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Kelly Hunt/Australian Defense Force/UPI/LANDOV
Photos: The search for MH370
A member of the Royal New Zealand Air Force looks at a flare in the Indian Ocean during search operations on April 4, 2014.
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Nick Perry/Pool/Getty Images
Photos: The search for MH370
On March 30, 2014, a woman in Kuala Lumpur prepares for an event in honor of those aboard Flight 370.
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Rahman Roslan/Getty Images
Photos: The search for MH370
The sole representative for the families of Flight 370 passengers leaves a conference at a Beijing hotel on March 28, 2014, after other relatives left en masse to protest the Malaysian government's response to their questions.
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Ng Han Guan/AP
Photos: The search for MH370
A member of the Royal Australian Air Force is silhouetted against the southern Indian Ocean during the search for the missing jet on March 27, 2014.
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Michael Martina/Pool/Getty Images
Photos: The search for MH370
Flight Lt. Jayson Nichols looks at a map aboard a Royal Australian Air Force aircraft during a search on March 27, 2014.
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Michael Martina/Pool/AP
Photos: The search for MH370
People in Kuala Lumpur light candles during a ceremony held for the missing flight's passengers on March 27, 2014.
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Aaron Favila/AP
Photos: The search for MH370
Malaysian Prime Minister Najib Razak, center, delivers a statement about the flight on March 24, 2014. Razak's announcement came after the airline sent a text message to relatives saying it "deeply regrets that we have to assume beyond any reasonable doubt that MH 370 has been lost and that none of those onboard survived."
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MOHD RASFAN/AFP/Getty Images
Photos: The search for MH370
Grieving relatives of missing passengers leave a hotel in Beijing on March 24, 2014.
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GOH CHAI HIN/AFP/Getty Images
Photos: The search for MH370
A passenger views a weather map in the departures terminal of Kuala Lumpur International Airport on March 22, 2014.
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Rufus Cox/Getty Images
Photos: The search for MH370
A Chinese satellite captured this image, released on March 22, 2014, of a floating object in the Indian Ocean, according to China's State Administration of Science. It was a possible lead in the search for the missing plane. Surveillance planes were looking for two objects spotted by satellite imagery in remote, treacherous waters more than 1,400 miles from the west coast of Australia.
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China's State Admiration of Science
Photos: The search for MH370
Satellite imagery provided by the Australian Maritime Safety Authority on March 20, 2014, showed debris in the southern Indian Ocean that could have been from Flight 370. The announcement by Australian officials raised hopes of a breakthrough in the frustrating search.
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Digital Globe/AMSA/Getty Images
Photos: The search for MH370
Another satellite shot provided by the Australian Maritime Safety Authority shows possible debris from the flight.
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DigitalGlobe/AMSA via Getty Images
Photos: The search for MH370
A distraught relative of a missing passenger breaks down while talking to reporters at Kuala Lumpur International Airport on March 19, 2014.
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AZHAR RAHIM/EPA/LANDOV
Photos: The search for MH370
On March 18, 2014, a relative of a missing passenger tells reporters in Beijing about a hunger strike to protest authorities' handling of information about the missing jet.
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Andy Wong/AP
Photos: The search for MH370
U.S. Navy crew members assist in search-and-rescue operations in the Indian Ocean on March 16, 2014.
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U.S. Navy/Eric A. Pastor/AP
Photos: The search for MH370
Members of the Chinese navy continue search operations on March 13, 2014. After starting in the sea between Malaysia and Vietnam, the plane's last confirmed location, search efforts expanded west into the Indian Ocean.
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XINHUA/LANDOV
Photos: The search for MH370
A Vietnamese military official looks out an aircraft window during search operations March 13, 2014.
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LUONG THAI LINH/EPA/LANDOV
Photos: The search for MH370
Malaysian air force members look for debris near Kuala Lumpur on March 13, 2014.
PHOTO:
Rahman Roslan/Getty Images
Photos: The search for MH370
Relatives of missing passengers wait for the latest news at a hotel in Beijing on March 12, 2014.
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Andy Wong/AP
Photos: The search for MH370
A member of the Vietnamese air force checks a map while searching for the missing plane on March 11, 2014.
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HOANG DINH NAM/AFP/Getty Images
Photos: The search for MH370
A Vietnamese air force plane found traces of oil that authorities had suspected to be from the missing Malaysia Airlines plane, the Vietnamese government online newspaper reported on March 8, 2014. However, a sample from the slick showed it was bunker oil, typically used to power large cargo ships, Malaysia's state news agency, Bernama, reported on March 10, 2014.
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EPA/TIENPHONG.VN
Photos: The search for MH370
A U.S. Navy Seahawk helicopter lands aboard the USS Pinckney to change crews on March 9, 2014, before returning to search for the missing plane in the Gulf of Thailand.
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Chris D. Boardman/U.S. Navy via Getty Images
Photos: The search for MH370
Buddhist monks at Kuala Lumpur International Airport offer a special prayer for the missing passengers on March 9, 2014.
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Lai Seng Sin/AP
Photos: The search for MH370
Members of a Chinese emergency response team board a rescue vessel at the port of Sanya in China's Hainan province on March 9, 2014.
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Zhao Yingquan/Xinhua/Landov
Photos: The search for MH370
The rescue vessel sets out from Sanya in the South China Sea on March 9, 2014.
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Zhao Yingquan/Xinhua/Landov
Photos: The search for MH370
Malaysian Prime Minister Najib Razak, center, arrives to meet family members of missing passengers at the reception center at Kuala Lumpur International Airport on March 8, 2014.
PHOTO:
MANAN VATSYAYANA/AFP/Getty Images
Photos: The search for MH370
A relative of two missing passengers reacts at their home in Kuala Lumpur on March 8, 2014.
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MOHD RASFAN/AFP/Getty Images
Photos: The search for MH370
Chinese police at the Beijing airport stand beside the arrival board showing delayed Flight 370 in red on March 8, 2014.
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MARK RALSTON/AFP/Getty Images
Photos: The search for MH370
Malaysia Airlines Group CEO Ahmad Juahari Yahya, front, speaks during a news conference at a hotel in Sepang on March 8, 2014. "We deeply regret that we have lost all contacts" with the jet, he said.
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Lai Seng Sin/AP
Low frequency signals can travel thousands of miles through water under favorable circumstances, at about 1 mile per second, Duncan said. But “at the moment (the sound) appears to be inconsistent with other data about the aircraft position,” he said.
That’s because researchers at Curtin University believe the sound came from an area thousands of miles to the northwest of the current search area in the southern Indian Ocean. And even then, they haven’t been able to pinpoint the source.
Duncan says his team has calculated an “uncertainty box” for the signal’s origin. It’s area that stretches some 2,485 miles in length from southeast to northwest across the Indian Ocean, and spans some 124 to 186 miles in width at its widest point.
The center of the long, narrow box is south of the tip of India, as shown in a map released Wednesday.
The university on Wednesday released an audio clip captured by one of the listening devices, off of Perth. Duncan says his team has sped up the recording 10 times to make it audible to the human ear.
It also shared charts of acoustic signal plots showing what various devices detected.
Searching in the right place?
The search for the missing Malaysia Airlines flight continues to focus along an arc hundreds of kilometers long, the area where investigators believe the Boeing 777 ran out of fuel, about 1,000 miles off the coast of Western Australia.
Martin Dolan, the chief commissioner with the Australian Transport Safety Bureau (ATSB), the organization leading the search into MH370 at the request of Malaysia, says an international team of experts continues to review the analysis of Inmarsat satellite data and aircraft performance.
In a television exclusive, Dolan told CNN’s “Erin Burnett OutFront” he remains confident the final resting place of MH370 is somewhere along that arc, the so-called “partial handshake” with the satellite:
“We’ve seen all the data. We’ve seen all the calculations. We are reviewing the calculations and are also developing our own model to cross check and verify that information,” Dolan told Burnett.
When asked last week about the underwater sound being analyzed by the team at Curtin University, along with Geoscience Australia, a government agency, Dolan was skeptical.
“We think that those detections may have been interesting from the point of view of the direction they came, but other characteristics make it unlikely that they are associated with MH370,” he said. The ATSB first referenced these signals in a document posted on its website on May 26.
As was the case with the Inmarsat satellite – a communications satellite whose data was analyzed by Malaysia Airlines MH370 investigators as a navigational aide – the analysis of the underwater signals involves the use of technology for a different purpose than its original intent.
One of the devices, operated by Curtin University and located some 12 miles off Perth, is designed to listen to whales and other marine life. The other is for signs of underwater nuclear explosions, one of 11 operated worldwide by the U.N.-chartered Comprehensive Test Ban Treaty Organization (CTBTO) as part of the International Monitoring System.
Early in the search for Malaysia Flight 370, the United Nations reported it had not detected any explosions or plane crashes on land or water from its sensors around the globe. But the recent efforts involve pairing CTBTO data with other sources to see what can be gleaned, officials said.
“One can always be hopeful,” said Mark Prior, a seismic acoustic analyst with the CTBTO.
The CTBTO’s hydro-acoustic stations detect low frequency sound in the 0-100 Hz range, and can’t detect black box “pings” in the 30-40 kHz range, officials said. “It’s possible (to detect a plane crash), but the circumstances that would allow it would have to be very particular,” said Prior.
Prior said some of those circumstances might include a sloping sea bed. Another possible scenario: the origin of the sound would need to be near the listening device.
The CTBTO’s system near Cape Leeuwin, the southwestern-most point of Australia, regularly captures signals of ice breaking noise from Antarctica and seismic activity from Indonesia, he said. “There are other scenarios that would allow (the hydrophones to detect a crash). But it’s not certain if there was an impact we would detect it,” Prior said.
Attempts were made following the 2009 crash of Air France 447 in the southern Atlantic Ocean to see if underwater listening devices had detected the plane’s impact. No data could be found.
Years later, after the plane was located, CTBTO again checked its data, and still was not able to identify signals related to the crash.
