There are a few well known warning signs, such as earthquakes in the vicinity of a known volcano. And, of course, smoke rising from a volcano.
It was one of the Earth's momentous times. Continents collided. Volcanoes erupted. Ocean currents shifted. Species ran amok.
Wouldn't it be nice if we could predict when a volcano was about to erupt? Scientists have recently taken a big step closer toward doing just this.
Geysers spout up where a column of underground water is heated to boiling by "magma," or molten rock, pushing the water upward.
Is Hawaii due for a new volcano? Learn about Hawaii's growing island on this Moment of Science.
Did you know beneath Yellowstone National Park is a reservoir of magma?