A Super-Volcano in California which erupted with devastating results hundreds of thousands of years ago has a vast reservoir of semi-molten magma measuring a staggering 240 cubic MILES, a new study has suggested.  The amount of magma in the Long Valley Caldera is so large it could support an eruption equivalent to the massive one which occurred 767,000 years ago, which released 140 cubic miles of material into the atmosphere.

By comparison, the 1980 Mount St Helens eruption resulted in the release of 0.29 cubic miles. While the Long Valley Caldera is unlikely to blow anytime soon, the report, written by scientists from the United States Geological Survey (USGS), the University of California, and the University of Rhode Island, said: “We can conclude the mid-crustal reservoir is still melt-rich. “We estimate the reservoir currently contains enough melt to support another super-eruption comparable in size to the caldera-forming eruption at 767 ka.” READ MORE