On volcanoes, a fissure is an elongated fracture or crack at the surface from which lava erupts. Fissure eruptions typically dwindle to a central vent after a period of hours or days. Occasionally ...

Lava flows come in a great variety of shapes and sizes. Nyiragongo is considered one of the most dangerous volcanoes in the world because of its particularly fast-moving lava, which can flow more ...