Volcanoes have always been held in awe. They are spectacular and sometimes extremely dangerous.
But volcanologists searching for clues as to why and when they will erupt have recently uncovered some remarkable characteristics. Volcanoes shape, build, and move our continents. Some scientists say they also supply the air we breathe and the water we drink. There is even the suggestion that they have a lot to do with the origins of life.
Volcanologists have to be both painstaking and courageous-frequently entering the very throat of a volcano during an eruption. Horizon visited them in Italy, Iceland, the Caribbean, Hawaii and Japan - as well as in England.