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

“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

Video Americans, Tourists, Reflect on Meaning of Thanksgiving

VOA garnered opinions from several people soon after November 13 Paris attacks, which colored many of their thoughts

Video Thais Send Security Concerns Down the River

In northern Thailand, the annual tradition of constructing floating baskets to carry away the year’s bad spirits highlights the Loy Krathong festival

Video Tree Houses - A Branch of American Dream

Workshops aimed at teaching people how to build tree houses have become widely popular in America in recent years

This forum has been closed.
Comment Sorting
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.
Islamic State Unfazed by Losses in Iraq, Syriai
November 26, 2015 5:21 AM
Progress in the U.S.-led effort to beat Islamic State on its home turf in Iraq and Syria has led some to speculate the terror group may be growing desperate. But counterterror officials say that is not the case, and warn the recent spate of terror attacks is merely part of the group’s evolution. VOA National Security correspondent Jeff Seldin has more.

Video Islamic State Unfazed by Losses in Iraq, Syria

Progress in the U.S.-led effort to beat Islamic State on its home turf in Iraq and Syria has led some to speculate the terror group may be growing desperate. But counterterror officials say that is not the case, and warn the recent spate of terror attacks is merely part of the group’s evolution. VOA National Security correspondent Jeff Seldin has more.

Video Taiwan Looks for Role in South China Sea Dispute

The Taiwanese government is one of several that claims territory in the hotly contested South China Sea, but Taipei has long been sidelined in the dispute, overshadowed by China. Now, as the Philippines challenges Beijing’s claims in an international court at The Hague, Taipei is looking to publicly assert its claims. VOA’s Bill Ide has more from Beijing.

Video Syrian Refugees in US Express Concern for Those Left Behind

Syrian immigrants in the United States are concerned about the negative tide of public opinion and the politicians who want to block a U.S. plan to accept 10,000 Syrian refugees. Zlatica Hoke reports many Americans are fighting to dispel suspicions linking refugees to terrorists.

Video After Paris Attacks, France Steps Up Fight Against IS

The November 13 Paris attacks have drawn increased attention to Syria, where many of the suspected perpetrators are said to have received training. French President Francois Hollande is working to build a broad international coalition to defeat Islamic State in Syria and in Iraq. Zlatica Hoke reports.

Video US, Cambodian Navies Pair Up in Gulf of Thailand

The U.S. Navy has deployed one of its newest and most advanced ships to Cambodia to conduct joint training drills in the Gulf of Thailand. Riding hull-to-hull with Cambodian ships, the seamen of the USS Fort Worth are executing joint-training drills that will help build relations in Southeast Asia. David Boyle reports for VOA from Preah Sihanouk province.

Video Americans Sharpen Focus on Terrorism

Washington will be quieter than usual this week due to the Thanksgiving holiday, even as Americans across the nation register heightened concerns over possible terrorist threats. VOA’s Michael Bowman reports new polling data from ABC News and the Washington Post newspaper show an electorate increasingly focused on security issues after the deadly Islamic State attacks in Paris.

Video World Leaders Head to Paris for Climate Deal

Heads of state from nearly 80 countries are heading to Paris (November 30-December 11) to craft a global climate change agreement. The new accord will replace the Kyoto Protocol on Climate Change that expired in 2012.

Video Uncertain Future for Syrian Refugee Resettlement in Illinois

For the trickle of Syrian refugees finding new homes in the Midwest city of Chicago, the call to end resettlement in many U.S. states is adding another dimension to their long journey fleeing war. Organizations working to help them integrate say the backlash since the Paris attacks is both harming and helping their efforts to provide refugees sanctuary. VOA's Kane Farabaugh reports.

Video Creating Physical Virtual Reality With Tiny Drones

As many computer gamers know, virtual reality is a three-dimensional picture, projected inside special googles. It can fool your brain into thinking the computer world is the real world. But If you try to touch it, it’s not there. Now Canadian researchers say it may be possible to create a physical virtual reality using tiny drones. VOA’s George Putic reports.

Video New American Indian Village Takes Visitors Back in Time

There is precious little opportunity to experience what life was like in the United States before its colonization by European settlers. Now, an American Indian village built in a park outside Washington is taking visitors back in time to experience the way of life of America's indigenous people. Carol Pearson narrates this report from VOA's June Soh.

Video Even With Hometown Liberated, Yazidi Refugees Fear Return

While the northern Iraqi town of Sinjar has been liberated from Islamic State forces, it's not clear whether Yazidi residents who fled the militants will now return home. VOA’s Mahmut Bozarslan talked with Yazidis, a religious and ethnic minority, at a Turkish refugee camp in Diyarbakır. Robert Raffaele narrates his report.

Video Nairobi Tailors Make Pope Francis’ Vestments

To ensure the pope is properly attired during his visit, the Kenya Conference of Catholic Bishops asked the Dolly Craft Sewing Project in the Nairobi slum of Kangemi to make the pope's vestments, the garments he will wear during the various ceremonies. Jill Craig reports.

Video Cross-Border Terrorism Puts Europe’s Passport-Free Travel in Doubt

The fallout from the Islamic State terror attacks in Paris has put the future of Europe’s passport-free travel area, known as the "Schengen Zone," in doubt. Several of the perpetrators were known to intelligence agencies, but were not intercepted. Henry Ridgwell reports from London European ministers are to hold an emergency meeting Friday in Brussels to look at ways of improving security.

Video El Niño Brings Unexpected Fish From Mexico to California

Fish in an unexpected spectrum of sizes, shapes and colors are moving north, through El Niño's warm currents from Mexican waters to the Pacific Ocean off California’s coast. El Nino is the periodic warming of the eastern and central Pacific Ocean. As Faiza Elmasry tells us, this phenomenon thrills scientists and gives anglers the chance of a once-in-a-lifetime big catch. Faith Lapidus narrates.

Video Terrorism in Many Forms Continues to Plague Africa

While the world's attention is on Paris in the wake of Friday night's deadly attacks, terrorism from various sides remains a looming threat in many African countries. Nigerian cities have been targeted this week by attacks many believe were staged by the violent Islamist group Boko Haram. In addition, residents in many regions are forced to flee their homes as they are terrorized by armed militias. Zlatica Hoke reports.

Video Study: Underage Marriage Rate Higher for Females in Pakistan

While attitudes about the societal role of females in Pakistan are evolving, research by child advocacy group Plan International suggests that underage marriage of girls remains a particularly big issue in the country. VOA’s Ayesha Tanzeem reports how such marriages leads to further social problems.

VOA Blogs