News / Science & Technology

Researchers Record Iceberg Breaking Loud as an Earthquake

A view of the leading edge of the remaining part of the Larsen B ice shelf that extends into the northwest part of the Weddell Sea, March 4, 2008.
A view of the leading edge of the remaining part of the Larsen B ice shelf that extends into the northwest part of the Weddell Sea, March 4, 2008.
Megan McGrath
Human-made sound in the world’s oceans, such as ship noise or seismic testing, may interfere with marine animals’ ability to use sound effectively for essential navigation and communication. Researchers collecting audio recordings in the Antarctic Weddell Sea have discovered that a melting iceberg can be a massive source of natural sound - in this case as loud as a magnitude-4 earthquake.

The sound can be mistaken as a stringed instrument like a double bass, or maybe some kind of truck on the highway. But it actually is an iceberg, in the Antarctic Weddell Sea, grinding slowly against the seafloor.

Researchers Catch Iceberg Breaking Loud as an Earthquake
Researchers Catch Iceberg Breaking Loud as an Earthquakei
|| 0:00:00
...    
🔇
X

“The iceberg is essentially scraping along and more or less resonating, kind of like a tuning fork,” explained Robert Dziak of Oregon State University.

Dziak led a team of scientists monitoring a collection of underwater microphones around the Antarctic Peninsula, the northernmost part of the southern continent. They detected the sounds of an iceberg being born, as it cracked off the ice of the mainland. “It’s big. It’s about 25 by 50 kilometers in dimension, length and width. So it’s essentially a little floating island out there that’s moving around in the Southern Ocean.”
 
Over the course of its life, from its calving to its journey toward warmer seas to its eventual melting, the iceberg was never out of range of the team’s microphones.

"We saw from the beginning to its actual eventual death, for lack of a better word,” he stated.

Dziak believes this is the first time anyone has listened to a single iceberg for its entire life. And what his team heard when the iceberg floated into the warmer Scotia Sea was astonishing.

“As it begins to enter warmer water, it begins to melt. And it can melt catastrophically,” he said. “The sound of this iceberg breaking apart was incredibly loud, equivalent to several hundred supertankers in noise level.”

That’s as loud as a small earthquake, Dziak said, loud enough to resonate all the way up to the equator.

The oceanographers wondered if this much noise could pose a problem for marine animals, which use sound to navigate, communicate and find food. Bioacoustician Chris Clark of Cornell University studies the effect of underwater sound on ocean life.

“Whales, and fishes, as a matter of fact, and now even all the invertebrates, like the lobsters and the shrimp and crabs and things like that, are all paying attention to sound,” said Clark. “There’s been this increasing awareness and concern about noise in the ocean - is it good, is it bad, are we indifferent, what’s going on?”

Human-created sound in the ocean is on the rise, from increased shipping traffic, seismic testing and military sonar, and researchers are demonstrating more and more that ocean life is being affected. The noise, Clark said, can make it impossible for animals to hear the things they need to hear in order to live.

“We refer to it as acoustic bleaching,” explained Clark. “It’s as though suddenly there’s a big fog bank that just comes into where you’re living and suddenly you can’t see very far, only in this case the fog bank is noise.”

But Clark said that temporary, natural sounds - like an iceberg cracking apart, though they may be as loud as an earthquake - are probably not nearly as harmful to marine life as manmade sounds. “It’s one thing to have evolved over 5 or 6 million years in a world that’s dynamic, with storms, with ice. The human-generated noise in the ocean is so chronically persistent, it’s now a real concern, and it dwarfs collective noise generated by icebergs,” he said.

Still, researchers say this is a time of warming oceans. Climate change may lead to more polar ice breaking apart, and shattering loud like earthquakes in the Southern seas.

You May Like

Arrested Football Officials Come Mainly From the Americas

US Justice Department alleges defendants participated in 24-year scheme to enrich themselves through corruption of international soccer More

Video Kenyans Lament Al-Shabab's Recruitment of Youths

VOA travels to Isiolo, where residents share their fears, struggles to get loved ones back from Somalia-based militant group More

This US Epidemic Keeps Getting Worse

One in 4 Americans suffers from this condition More

This forum has been closed.
Comment Sorting
Comments
     
by: Yoshi from: Sapporo
July 16, 2013 11:16 PM
I have heard the sound of breaking iceberg for the first time. I wonder if icebergs continue to make sounds when they are moving into warmer sea and melting down. Thank you.

by: Clyde Duncan from: Vancouver, Canada
July 16, 2013 12:49 PM
I am surprised that there was no mention in the article about the mysterious beaching of whales and other sea creatures. Could the noise pollution be causing this activity?? I have not seen or heard of this consideration, before now.

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
A Small Oasis on Kabul's Outskirts Provides Relief From Security Tensionsi
X
May 26, 2015 11:11 PM
When people in Kabul want to get away from the city and relax, many choose Qargha Lake, a small resort on the outskirts of Kabul. Ayesha Tanzeem visited and talked with people about the precious oasis.
Video

Video A Small Oasis on Kabul's Outskirts Provides Relief From Security Tensions

When people in Kabul want to get away from the city and relax, many choose Qargha Lake, a small resort on the outskirts of Kabul. Ayesha Tanzeem visited and talked with people about the precious oasis.
Video

Video Film Festival Looks at Indigenous Peoples, Culture Conflict

A recent Los Angeles film festival highlighted the plight of people caught between two cultures. Mike O'Sullivan has more on the the Garifuna International Film Festival, a Los Angeles forum created by a woman from Central America who wants the world to know more about her culture.
Video

Video Kenyans Lament Losing Sons to al-Shabab

There is agony, fear and lost hope in the Kenyan town of Isiolo, a key target of a new al-Shabab recruitment drive. VOA's Mohammed Yusuf visits Isiolo to speak with families and at least one man who says he was a recruiter.
Video

Video Scientists Say Plankton More Important Than Previously Thought

Tiny ocean creatures called plankton are mostly thought of as food for whales and other large marine animals, but a four-year global study discovered, among other things, that plankton are a major source of oxygen on our planet. VOA’s George Putic reports.
Video

Video US-led Coalition Gives Some Weapons to Iraqi Troops

In a video released Tuesday from the Iraqi Ministry of Defense, Iraqi forces and U.S.-led coalition troops survey a cache of weapons supplied to help Iraq liberate Mosul from Islamic State group. According to a statement provided with the video, the ministry and the U.S.-led coaltion troops have started ''supplying the 16th army division with medium and light weapons in preparation to liberate Mosul and nearby areas from Da'esh (Arabic acronym for Islamic State group).''
Video

Video Amnesty International: 'Overwhelming Evidence' of War Crimes in Ukraine

Human rights group Amnesty International says there is overwhelming evidence of ongoing war crimes in Ukraine, despite a tentative cease-fire with pro-Russian rebels. Researchers interviewed more than 30 prisoners from both sides of the conflict and all but one said they were tortured. Henry Ridgwell reports for VOA from London.
Video

Video Washington Parade Honors Those Killed Serving in US Military

Every year, on the last Monday in the month of May, millions of Americans honor the memories of those killed while serving in the armed forces. Memorial Day is a tradition that dates back to the 19th Century. While many people celebrate the federal holiday with a barbecue and a day off from work, for those who’ve served in the military, it’s a special day to remember those who made the ultimate sacrifice. Arash Arabasadi reports for VOA from Washington.
Video

Video Kenya’s Capital Sees Rise in Shisha Parlors

In Kenya, the smoking of shisha, a type of flavored tobacco, is the latest craze. Patrons are flocking to shisha parlors to smoke and socialize. But the practice can be addictive and harmful, though many dabblers may not realize the dangers, according to a new review. Lenny Ruvaga has more on the story for VOA from Nairobi, Kenya.
Video

Video Rolling Thunder Run Reveals Changed Attitudes Towards Vietnam War

For many US war veterans, the Memorial Day holiday is an opportunity to look back at a divisive conflict in the nation’s history and to remember those who did not make it home.
Video

Video Female American Soldiers: Healing Through Filmmaking

According to the United States Defense Department, there are more than 200-thousand women serving in the U.S. Armed Forces.  Like their male counterparts, females have experiences that can be very traumatic.  VOA's Bernard Shusman tells us about a program that is helping some American women in the military heal through filmmaking.

VOA Blogs