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

days before the volcano erupted. A large fissure has opened up nearby, at the Sundhnukagígar crater north of Grindavik, with lava flowing both east and west. One estimate by the country's Met ...