Top Ten Famous Volcanoes Kilauea, Hawaii Location: 19.4N, 155.3W Elevation: 4,009 feet (1,222 m) Kīlauea is an active volcano in the Hawaiian Islands , one of five shield volcanoes that together form the Island of Hawai i.
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The word "volcano" comes from the little island of Vulcano in the Mediterranean Sea off Sicily. Centuries ago, the people living in this area believed that Vulcano was the chimney of the forge of Vulcan -- the blacksmith of the Roman gods. They thought that the hot lava fragments and clouds of dust erupting form Vulcano came from Vulcan's forge as he beat out thunderbolts for Jupiter, king of the gods, and weapons for Mars, the god of war. In Polynesia the people attributed eruptive activity to the beautiful but wrathful Pele, Goddess of Volcanoes, whenever she was angry or spiteful. Today we know that volcanic eruptions are not super-natural but can be studied and interpreted by scientists.
Volcano1. Magma chamber2. Country rock3. Conduit (pipe)4. Base5. Sill6. Branch pipe7. Layers of ash emitted by the volcano8. Flank9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15. Ash cloud
A volcano is an opening (or rupture) in the Earth's surface or crust, which allows hot, molten rock, ash, and gases to escape from deep below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.
Volcanoes are generally found where two to three tectonic platespull apart or are coming together. A mid-oceanic ridge, like the Mid-Atlantic Ridge, has examples of volcanoes caused by "divergent tectonic plates" pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by "convergent tectonic plates" coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another (like the San Andreas fault). Volcanoes can also form where there is stretching of the Earth's crust and where the crust grows thin (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley or the European Rhine Graben with its Eifel volcanoes).
Finally, volcanoes can be caused by "mantle plumes," so-called "hotspots;" these hotspots can occur far from plate boundaries, such as the Hawaiian Islands. Interestingly, hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.
The Pacific Ring of Fire is a zone of frequent earthquakes and volcanic eruptions encircling the basin of the Pacific Ocean. It is sometimes called the circum-Pacific belt or the circum-Pacific seismic belt.
The "Ring of Fire" is an arc stretching from New Zealand, along the eastern edge of Asia, north across the Aleutian Islands of Alaska, and south along the coast of North and South America. It is composed over 75% of the world's active and dormant volcanoes.
Ring of Fire is located at the borders of the Pacific Plate and other major tectonic plates.
Around the Ring of Fire, the Pacific Plate is colliding with and sliding underneath other plates. This process is known as subduction and the volcanically and seismically active area nearby is known as a subduction zone. There is a tremendous amount of energy created by these plates and they easily melt rock into magma, which rises to the surface as lava and forms volcanoes.
According to the new, generally accepted "plate-tectonics" theory, scientists believe that the Earth's surface is broken into a number of shifting slabs or plates, which average about 50 miles in thickness. These plates move relative to one another above a hotter, deeper, more mobile zone at average rates as great as a few inches per year.
Most of the world's active volcanoes are located along or near the boundaries between shifting plates and are called "plate-boundary" volcanoes. However, some active volcanoes are not associated with plate boundaries, and many of these so-called "intra-plate" volcanoes form roughly linear chains in the interior of some oceanic plates.
The Hawaiian Islands provide perhaps the best example of an "intra-plate" volcanic chain, developed by the northwest-moving Pacific Plate passing over an inferred "hot spot" that initiates the magma-generation and volcano-formation process.
The peripheral areas of the Pacific Ocean Basin, containing the boundaries of several plates are dotted by many active volcanoes that form the so-called "Ring of Fire".