Ecuador - the earth definitely moved?

The term "earth-shattering" is a throw-away advertising cliche used to describe anything from a free cola with a burger meal to a new-year furniture sale.

If you really want to see earth shattering in its terrible, awesome splendour, don't go to Burger King or DFS, go to somewhere like Quilotoa in Ecuador.

This really was earth-shattering - about 800 years ago, Quilotoa (the most westerly of Ecuador's big volcanoes) exploded with a violence that's almost incomprehensible.

This was a level 6 on the volcanic scale of eruptions and to put that into context Eyjafjallajökull (the troublesome volcano in Iceland that brought air travel to a halt four years ago) managed a 4; and Vesuvius, in the process of destroying Pompeii and Herculaneum, reached level 5. The VEI scale is logarithmic, which means each level is 10 times more powerful than the previous.

When Quilotoa exploded in 1280, it was 10 times more powerful than Vesuvius in 79CE. Krakatoa was also a 6 and the only eruptions bigger than this have been way into pre-history. More than 10 cubic kilometres of rock was blown into the sky, the ash plume would have reached over 50,000ft, lahars and pyroclastic flows reached the Pacific ocean. It would have changed the earth's climate for a couple of years.

So I find myself standing on the crater rim of Quilotoa trying to take this in. It's awesome; certainly the most dramatic and spectacular natural phenomenon I've ever seen. What's left 800 years after this massive explosion is a vast crater two miles across and six miles in circumference; 900ft below me is the surface of a blue-green crater lake. The viewing platform is at 3800m.

Max would tell you this is a caldera; it's what happens when the top of a volcano blows off with massive force and the magma chamber below empties. No longer able to support the weight of earth above, the chamber collapses into a cauldron shape, which is the lake we can see from the crater rim.

This massive geological feature isn't the volcano, it's what's left of the volcano. You would not want to have been standing here in 1280!

Panorama taken on iPhone of the crater lake of Quilotoa.

There's also a video here, shame it's so noisy (the wind was very strong).