Why is it dangerous to dive/swim into a glacier river?

Question

I’ve seen a Youtube video of a man throwing a big rock in a glacier river at Matanuska glacier and the camera man asked “Is that an echo?”

I browsed the comment section and the comment theme tells me it is dangerous and death awaits when you dive.

In: Planetary Science

Answer 1

Glacier rivers are dangerously cold, and immersion can quickly lead to hypothermia, which impairs your ability to move and think. Plus, these rivers often have strong currents and hidden underwater hazards like sharp rocks and crevices that can trap or injure you. The echo might come from hollow ice or cavities beneath the surface, amplifying the sound.