Icebergs produce sound, each one with a particular acoustic signature that can help in identifying the current state of a large chunk of ice floating in the ocean. Specifically, an acoustic signature accompanies the moment an iceberg calves away from bigger sheets of ice, the monitoring of which could help researchers in determining how much ice is melting.

In a study published in the journal Geophysical Research Letters, researchers used underwater microphones called hydrophones to listen in on iceberg acoustics. Sounds represent distinct activities and this has helped the researchers in figuring out what is currently happening to an iceberg.

By combining sound data they collected with time-lapse images, researchers discovered different sounds were made depending on the type of iceberg developing. From a tidal glacier, for instance, they isolated three acoustic signatures.

With that kind of information, they were not only able to work out just how much of the ice is crumbling into pieces but also determine at what stage a break up is, even if the event was taking place beneath the water's surface.

Studying submarine events is highly difficult. Disintegration happens underwater so it cannot be readily observed. However, every point an ice reaches as it breaks off from a bigger piece creates a distinct sound. By listening to every crack, researchers will know what's happening to an iceberg, even if they don't see it.

Researchers from the University of Silesia, University of Gdansk, University of Bath, Scripps Institution of Oceanography and the Center for Polar Studies are particularly interested in the events surrounding an iceberg because a better understanding of calving will offer better estimates of mass being lost from glaciers due to global warming.

Mostly, icebergs are currently monitored using satellite technology. The U.S. National Ice Center relies on satellite data for tracking icebergs near Antarctica bigger than 5,400 square feet. The International Ice Patrol, however, uses a combination of aerial surveys and radars to keep tabs on icebergs along major shipping routes.

Icebergs come in various shapes and sizes, ranging from chunks the size of ice cubes to islands of ice comparable to a small country. Technically though, an iceberg is any chunk of ice bigger than 16 feet across. Smaller icebergs are called growlers and bergy bits. Since they are smaller in size, they are more difficult to spot, making them more dangerous to ships. Icebers are mostly found in Antarctica and the North Atlantic.