Ordinary volcanoes are formed by a column of very hot molten rock, known (0) as magma, rising to the earth’s surface from deep within the Earth’s core. This type (1) volcano usually erupts from the top of a cone-shaped mountain, such as the famous volcano, Vesuvius, near Naples in Italy. However, there is (2) kind of volcano, called a supervolcano. It is one of the (3) destructive forces in nature but also one of the least understood. One thing that is known, though, is that if a supervolcano occurs, it (4) lead to mass extinction of species, and one species in particular (5) will be under threat is the human race. So what is a supervolcano exactly, and (6) often do they occur? A supervolcano is basically a huge reservoir, or lake, of boiling magma that lies close to the Earth’s surface. They (7) found in six different regions of the planet. One of the most famous supervolcano regions is in Yellowstone Park in Wyoming, USA. This park is (8) area of outstanding natural beauty but it is also a sleeping giant that could wake (9) at any time. The last time the area erupted was (10) than 600,000 years ago and a new eruption is now overdue. When it does erupt - and (11) day it will - it will virtually destroy the USA. And the dust cloud it creates will block (12) the sun causing the Earth’s temperature to plummet, threatening the whole planet with mass extinction.
