1 | In the years running up to the explosion a large dome of lava a few hundred metres across had grown. | |
2 | A rainy day increased the likelihood of dome collapse from 1.5 per cent to 16 per cent. "It wouldn't have to be spectacularly heavy rainfall, " says Matthews. | |
3 | It formed when a volcanic dome hardened and gradually eroded, exposing the onion-like layers of rock. | |
4 | Light brown ash covers the snow above the flow deposits, and a tiny plume rises from Shiveluch's growing lava dome. Vegetation surrounding the volcano is colored dark red. | |
5 | If this collapsed, it would send deadly 'pyroclastic' flows of super-hot gas and rocks towards the occupied areas. |