Lava balloons

You Wouldn't Expect That! - Lava Balloons

I came across this article and found it amazing! Read and be astonished!

Lava balloons are pieces of hollow, cooled lava burped up from the seafloor after some types of undersea volcanic eruptions. This balloon was recovered from the 1998–2001 eruption near the Azores, Portugal. Credit: Ulrich Küppers.

Lava balloons floating in the ocean on 18 January 2012 during an eruption off the coast of the Canary Islands, Spain. Credit: Laura García-Cañada, CC BY 3.0