Why Does Earth Have Volcanoes?

When you hear the word "volcano" you probably picture a mountain spewing lava and hot ash into the sky, but there are several types of them.

TestTube Plus is built for enthusiastic science fans seeking out comprehensive conversations on the geeky topics they love. Host Trace Dominguez digs beyond the usual scope to deliver details, developments and opinions on advanced topics like AI, string theory and Mars exploration. TestTube Plus is also offered as an audio podcast on iTunes.