A volcano is a mountain that opens downward to a pool of magma below the crust. When pressure builds up due to a buildup of magma, eruptions occur. There are different types of eruptions, the most common being when magma is released from the volcano's vent. Gases and rocks can also shoot up through the vent and fill the air with lava fragments creating ash clouds. Eruptions can cause lateral blasts, lava flows, hot ash flows, mudslides, avalanches, falling ash and floods. Here are some brief descriptions of the different types of explosions.The type of erruption is commonly labeled with the name of a volcano which has acted in a similar way during eruption.
E.G: "Strombolian," "Vulcanian," "Vesuvian," "Pelean," "Hawaiian,"
Hawaiian Eruption
In a Hawaiian eruption, fluid lava is thrown into the air in jets from a vent on the summit, or linear vents (fissures) around the flank. The jets known as 'fire fountains' can last for hours or even days. The spatter created by bits of hot lava falling out of the fountain can melt together and form lava flows, or build hills called spatter cones. Lava flows may also come from vents and due to these flows being very runny, they can travel very long distances from their source before hardening.
Hawaiian eruptions get their names from the Kilauea volcano on the Big Island of Hawaii, which is famous for producing spectacular fire fountains.
Plinian Eruption
These are the largest and most violent types of eruptions in which lots of gasses and ash are violently ejected to heights of several miles. They release enormous amounts of energy at speeds of hundreds of meters per second. Ash from an eruption column can drift or be blown hundreds or thousands of miles away from the volcano. The eruption columns are usually shaped like a mushroom.
Plinian eruptions, are also known as Vesuvian eruptions, due to their similarity to the eruption of Mount Vesuvius in AD 79.
Plinian eruptions are extremely destructive, and can even obliterate the entire top of a mountain, as occurred at Mount St. Helens in 1980. They can produce falls of ash, scoria and lava bombs miles from the volcano, and pyroclastic density currents that raze forests, strip soil from bedrock and obliterate anything in their paths. These eruptions are often climactic, and a volcano with a magma chamber emptied by a large Plinian eruption may subsequently enter a period of inactivity.
*** FACT ***
Mount Vesuvius could erupt at any time, it has been overdue.
E.G: "Strombolian," "Vulcanian," "Vesuvian," "Pelean," "Hawaiian,"
Hawaiian Eruption
In a Hawaiian eruption, fluid lava is thrown into the air in jets from a vent on the summit, or linear vents (fissures) around the flank. The jets known as 'fire fountains' can last for hours or even days. The spatter created by bits of hot lava falling out of the fountain can melt together and form lava flows, or build hills called spatter cones. Lava flows may also come from vents and due to these flows being very runny, they can travel very long distances from their source before hardening.
Hawaiian eruptions get their names from the Kilauea volcano on the Big Island of Hawaii, which is famous for producing spectacular fire fountains.
Plinian Eruption
These are the largest and most violent types of eruptions in which lots of gasses and ash are violently ejected to heights of several miles. They release enormous amounts of energy at speeds of hundreds of meters per second. Ash from an eruption column can drift or be blown hundreds or thousands of miles away from the volcano. The eruption columns are usually shaped like a mushroom.
Plinian eruptions, are also known as Vesuvian eruptions, due to their similarity to the eruption of Mount Vesuvius in AD 79.
Plinian eruptions are extremely destructive, and can even obliterate the entire top of a mountain, as occurred at Mount St. Helens in 1980. They can produce falls of ash, scoria and lava bombs miles from the volcano, and pyroclastic density currents that raze forests, strip soil from bedrock and obliterate anything in their paths. These eruptions are often climactic, and a volcano with a magma chamber emptied by a large Plinian eruption may subsequently enter a period of inactivity.
*** FACT ***
Mount Vesuvius could erupt at any time, it has been overdue.
Surtseyan Eruption
Surtseyan eruptions occur when magma or lava interacts explosively with water. In most cases, Surtseyan eruptions occur when an undersea volcano has finally grown large enough to break the water's surface; because water expands when it turns to steam, water that comes into contact with hot lava explodes and creates plumes of ash, steam and scoria. Lavas created by a Surtseyan eruption tend to be basalt, since most oceanic volcanoes are basaltic.
The classic example of a Surtseyan eruption was the volcanic island of Surtsey, which erupted off the south coast of Iceland between 1963 and 1965. Hydromagmatic (water and magma) activity built up several square kilometers of tephra (rock particles) over the first several months of the eruption; eventually, seawater could no longer reach the vent, and the eruption then transitioned to a Hawaiian eruption.
Vulcanian Eruption
A Vulcanian eruption is a short, violent, relatively small explosion of viscous magma (usually andesite, dacite, or rhyolite). This type of eruption results from the fragmentation and explosion of a plug of lava in a volcanic conduit, or from the rupture of a lava dome (viscous lava that piles up over a vent). Vulcanian eruptions create powerful explosions in which material can travel faster than 350 meters per second (800 mph) and rise several kilometers into the air. They produce tephra, ash clouds, and pyroclastic density currents (clouds of hot ash, gas and rock that flow almost like fluids).
Vulcanian eruptions may be repetitive and go on for days, months, or years, or they may precede even larger explosive eruptions.
Surtseyan eruptions occur when magma or lava interacts explosively with water. In most cases, Surtseyan eruptions occur when an undersea volcano has finally grown large enough to break the water's surface; because water expands when it turns to steam, water that comes into contact with hot lava explodes and creates plumes of ash, steam and scoria. Lavas created by a Surtseyan eruption tend to be basalt, since most oceanic volcanoes are basaltic.
The classic example of a Surtseyan eruption was the volcanic island of Surtsey, which erupted off the south coast of Iceland between 1963 and 1965. Hydromagmatic (water and magma) activity built up several square kilometers of tephra (rock particles) over the first several months of the eruption; eventually, seawater could no longer reach the vent, and the eruption then transitioned to a Hawaiian eruption.
Vulcanian Eruption
A Vulcanian eruption is a short, violent, relatively small explosion of viscous magma (usually andesite, dacite, or rhyolite). This type of eruption results from the fragmentation and explosion of a plug of lava in a volcanic conduit, or from the rupture of a lava dome (viscous lava that piles up over a vent). Vulcanian eruptions create powerful explosions in which material can travel faster than 350 meters per second (800 mph) and rise several kilometers into the air. They produce tephra, ash clouds, and pyroclastic density currents (clouds of hot ash, gas and rock that flow almost like fluids).
Vulcanian eruptions may be repetitive and go on for days, months, or years, or they may precede even larger explosive eruptions.