Fireworks on a global scale

cover for the book EruptionWe all know about volcanoes right? After all here in Christchurch we’re virtually sitting on one which provides both of our local harbours.

But did you know about supervolcanoes? They’ve been in the news lately because at the best known one in Yellowstone National Park scientists have just finished measuring its magma chamber. It’s even bigger than they thought at fifty five miles across. That’s a lot of lava.

The other one you will have heard of is Lake Taupo, which is what remains of a supervolcano that exploded 65,000 years ago thereby helping to form the central plateau of the North Island.

The thing about supervolcanoes, of which there are a number on earth (estimates vary) and others known on Mars and Jupiter’s moon Io, is that they are also super spectacular. When magma from a chamber 55 miles across explodes it is world changing. When Taupo went up, evidence was noted by the Romans on the other side of the world in the form of unusual sunsets. It is thought that one in Siberia was responsible for what is known as “the great dying” the greatest extinction event on earth of all time.

Fortunately they only blow very occasionally, even in terms of geological timescales so you don’t need to lose any sleep over them. You don’t need to worry about our own Banks Peninisula volcano either by the way. It was pretty big but its magma chamber is empty.