The holes drilled into Arctic, Antarctic, and glacial ice to harvest ice cores can be up to 2 miles deep. One of my all-time favorite sounds is created by dropping ice down into one of these holes — it makes a super-cool pinging noise, as demonstrated in these two videos:
Ice makes similar sounds under other conditions, like if you skip rocks on a frozen lake:
Or skate on really thin ice (ok this might actually be my favorite sound, with apologies to the ice core holes):
Headphones are recommended for all of these videos. The explanation for this distinctive pinging sound, which sounds like a Star Wars blaster, has to do with how fast different sound frequencies move through the ice, as explained in this video:
(via the kid should see this)