Icebergs' Sound

Twenty years ago, not so long before B-15 broke off from Antarctica, "we didn't even know that icebergs made [blank] ," says Haru Matsumoto, an ocean engineer at NOAA who studied these sounds. But [blank] the past few years, scientists have started to learn to distinguish the eerie, haunting sounds of iceberg life ice cracking, icebergs grinding against each other, an iceberg grounding on the seafloor and measure the extent to [blank] those sounds contribute to the noise of the ocean. While they're just now learning to listen, the sounds [blank] ice could help them understand the behavior and breakup of icebergs and ice shelves as the poles warm [blank] .