4 ms·

volcano

• mark-r 9y ago
  That was my first thought too, but would an underwater volcano create such a large hole or would the effect be more localized? It should be easy to verify.
  • bigiain 9y ago
    And why would it be seasonal/annual? (I think it's Cthulhu. I pray I get eaten first...)
    • mark-r 9y ago
      Perhaps in the winter it gets cold enough to overcome the effect, and a thin layer of ice gets formed? That would imply an eruption that lasts over a year though. An underground version of Yellowstone?
      • Taniwha 9y ago
        it's just the end of winter ... normally one would expect such a change at the end of summer, 5-6 months from now