Buzz
You’ve likely heard that satisfying fizz and crackle when you pour a drink over ice—it's a sound often recreated in soda commercials, like this one:
This intriguing sound is the result of a phenomenon called differential expansion. Usually, the beverage you're adding ice to is warmer than the ice itself (hence the need for ice). When the cold ice is submerged in the warmer drink, the outer layer of ice heats up and expands, while the inner layer remains cold and does not expand. Periodic Videos describes it as a "tug of war" between the two layers, causing the crackling noise.
If you allow ice cubes to warm up on a tray or in a bucket before adding them to your drink, you’re unlikely to hear the same popping and cracking sounds.
This sound phenomenon isn't exclusive to your soda. Glaciers experience a similar event as they melt, but on a much grander scale:
The sound is known as bergy seltzer (or sometimes spelled "bergie seltzer"), and it's caused when air bubbles trapped deep within glaciers burst as the ice melts and cracks. Unlike the crackling of your ice-filled drink, each pop of Bergy Seltzer carries a bit of history. The air bubbles were sealed in the glaciers when the ice originally formed, and when they release, the air can be thousands of years old.
