As I expect most people know there have been a small number of what is termed Super-Volcanoes. The volcano at Yellowstone is probably the most well known but it’s not the only one and it may not be the next one to, um, blow. News from Discovery news today indicates that there may (or may not) be a new one forming in Bolivia on the Altiplano Plateau.
A large part of this plain is inflating like a baloon, magma is gathering under the surface and covers an area similar in size to the Yellowstone caldera. Now the amount of deformation of the ground is 20 cm, which sounds like not much, but that is 1-2 cm a year and they estimate the magma chamber to be taking in 1 m³ of magma per second. (About 10 times faster than the average volcano.)
So what do we know and what do we think will happen. What we know is that the existing volcano, Uturuncu, on the plain that is smack in the middle of this bulge has been considered dead. It last erupted 300,000 years ago. That length of time usually means dead volcano but the rise of magma under it says something is happening. Now data only goes back 20 years so to figure out what has been happening you look at things like has the shore line of this lake changed and has it been changing over thousands of years. They check lakes because water finds its own level so if the shore used to be a long ways up from where it is now then the land has been rising for a while.
But the shore has only been changing for a little while. What this means is that whatever is happening has only been happening for a short geologic time period. SO years and tens of years not centuries or longer. So it may be the start of a new super volcano. The rise is over to great an area to be just the magma for the old volcano in the center of it all. That volcanoes magma chamber may have been the start of this new one but this is a lot bigger than it would need and more than any of it’s past eruptions would indicate that it ever needed. But given the size of the deformation and the rate and that it has just started to build it will be a long time before this possible super volcano would be ready to erupt and in the mean time it looks like a good place to study the evolution and growth of what may be the most violent act our planet can do on its own.
- Scientists fear new super-volcano may be forming in Bolivia (theextinctionprotocol.wordpress.com)
- When is a volcano going to erupt again (wiki.answers.com)