A fissure eruption is a volcanic eruption that occurs in cracks, or fissures, along the sides of the volcano. These eruptions differ from the typical centralized eruption that emerges from the mouth of a crater.Know More
Fissures develop in volcanoes over time based on shifting in the earth's crust and the cumulative effective of lava and steam boiling on the inside. A fissure eruption occurs when the gases, lava and rock fragments inside the crater spill out through the cracks. The result is similar to gushing water that flows out of a crack in a toilet tank or a pitcher of water.
While fissure eruptions take place in many volcanoes throughout the world, they occur especially often in the volcanoes of Iceland and Hawaii. The San Diego State University geology website notes that 1783 fissure eruption in Iceland, called the Laki flow, caused the most expansive recorded lava flow.
In contrast to explosive eruptions, fissure eruptions do not produce much of an ejection through the top of the crater. The pressure pushes the lava and gases out of the cracks instead. Some fissure eruptions have rings of fire that form around the outside as the hot lava and gases pass through rocky mountain terrain.Learn more in Volcanoes
According to the Oregon State University Department of Geosciences, a volcanic eruption may become violent if pressure builds up inside the volcano for any reason. An explosive eruption is much more dangerous than a steady flow of magma and can spread ash and pyroclastic material over a wide area. The eruption of Mount Saint Helens in 1980 was a textbook example of a violent, explosive volcanic eruption.Full Answer >
The nature of a volcanic eruption is determined by the temperature, viscosity and the amount of dissolved gases in the magma, according to San Diego State University. These factors determine whether an eruption is calm and nonviolent or explosive.Full Answer >
According to the UCSB Geology Department, a volcanic eruption is defined as a volcanic event resulting in the emission of gases, lava, ash or other material from a volcano. These can manifest as a single eruptive pulse, an eruptive phase or an eruptive episode.Full Answer >
Shield volcanoes produce eruptions with lava that pours over the top of the summit and features low-density magma. There is a low quantity of ash during the eruption.Full Answer >