Eruptions may be explosive, or quiet lava flows. A volcano that is not expected to erupt again. Lava that is shot into the air like a geyser by the pressure of trapped gases within the magma. A fissure is an elongate fracture or crack at the surface from which lava erupts. To produce electric power from geothermal resources, underground reservoirs of steam or hot water are tapped by wells and the steam rotates turbines that generate electricity.
Most geysers are hot springs that episodically erupt fountains of hot water and steam.
A large mass of ice formed by compressed snow, which moves slowly under its own weight. Glaciers exist where, over a period of years, snow remains after summer's end and accumulates year after year. Molten rock erupted from a volcano. Lava can occur in flows, domes, fragments and as pillows formed underwater. Lava which is forced from the vent much like toothpaste from a tube, forming a half-ball shape over the vent.