Glacial ice consists of snow that has been extremely compressed and compacted. In the case of the inland ice in Greenland, this process may stretch over thousands or even millions of years before the ice is pushed into the sea by a glacier. As the layers of snow pile up, tiny bubbles of air are trapped and put under enormous pressure by the weight of the surrounding ice. When the glacial ice finally melts in the sea, these tiny bubbles of air are released with a quiet, explosive popping noise, adding up to a many-voiced sizzling. The icebergs that drift in the Arctic give off a constant sizzling sound which is loud enough to determine their position from under water. The phenomenon was first noted by the crews of submarines. It is also known as “bergy seltzer” due to its resemblance to the sound of fizzy drinks.
I recorded the audio excerpt in Greenland 2006. I collected some ice chunks from icebergs in a plastic bag during a ship tour and stored them in a bar for some hours before returning to my hotel room. Surprisingly the ice was not melted, there was not even water in the plastic bag. I put the ice scraps in the bathtub and recorded the sizzling with an underwater microphone. Later at home I applied a lot of noise reduction and transient designing to the recordings to get the sound that you can hear in the above MP3.