Wednesday, 11 December 2013

Yellowstone supervolcano 'even more colossal'

1 comment:

Ian Donaldson said...

Imagine a rectangle whose long side is the M4 going east from
Bristol. Fifty-five miles will take you to Swindon. Now go south for 20 miles on the A346 from Swindon via Marlborough to the A303 between Stonehenge and Andover.

For the other short side take the
A37 south from Bristol to Wells - about 20 miles. This rectangle is
about the area of the Yellowstone magma chamber.

Now think of a road one mile long, and imagine this set on end, vertically, under your feet. Now keep going down underground for five times that distance under the Mendips and Salisbury Plain This volume - 55 miles times 20 miles times 5 miles gives a rough idea of the volume of this molten rock. Hair-raising.