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At some places on earth surface thin layers of lava pour out of the vent and hard on top of previous layers
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How do shield volcanoes have wide bases?
Shield volcanoes are wide because they are made to function as an island, much to the surprise of many scientists. These volcanoes are enormously big, usually spreading out over 300 miles.
What are the 4 general types of volcanoes?
shield,cindercone,composite,extinict
What types of Volcanoes can occur far from any plate boundaries?
Shield volcanoes may occur far from any plate boundaries.
What is similar about cinder cone volcanoes and shield volcanoes?
Both shield volcanoes and cinder cones erupt low-viscosity basaltic lava and have eruptions that are only mildly explosive if at all.Cinder cones are small, steep-sloped volcanoes composed primarily of a chunky variety of basalt called scoria.Shield volcanoes are large, gently sloping volcanoes composed primarily of layers of lava flows.
How are composite volcanoes and shield volcanoes different?
Composite volcanoes or Stratovolcanoes are your typical cartoon image of volcanoes, very tall, narrow craters at the top, steeper sides often snow capped peaks. Shield volcanoes tend to not be as tall and have much more shallow sloping sides. The reason for this is due to their products and location. Composite volcanoes produce lava which is much more viscous (thicker) than shield volcanoes, which tend to produce a thinner runnier lava. This is due to the Silica (SiO2) content of the lavas. Composite volcanoes tend to be produced by more Acidic lavas (with a higher Silica content) where as shield volcanoes are produced by lavas with a more Basic composition, (a lower silica content). Composite volcanoes (Mt St Helens, Vesuvius, Mt Fugi) tend to be formed near destructive plate boundries where one tectonic plate is being subducted beneath another. When the subducted plate reaches roughly 700 km depth it begins to enter the Aesthenosphere, a layer of more ductile rock deep in the mantle. The water content of the subducted plate causes the aesthenosphere to partially melt. The molten magma begins to rise in plumes towards the surface. As the magma plume rises it has a lot of contact with the surrounding rocks it passes through, and it absorbs silica from them, arriving at the surface as a viscous silica rich melt. Shield volcanoes (Mauna Loa, Kiluea, Hekla) are more common over constructive plate margins where two plates are pulling apart. When the plates pull apart it de-pressurises the mantle beneath the plates and causes it to partially melt. The Magma rises up the cracks between the two retreating plates, with little contact to the surrounding rocks, and so picks up very little silica content. This causes it to reach the surface as a runny basic lava. The runny nature of shield volcanoes means that lava flows travel a long way from the volcano crater, causing little build up on the surrounding flanks of the volcano. The viscous nature of Composite volcanoes means that the lava doesn't travel very far and builds up on the sides of the volcanoes making them much steeper. Shield volcanoes are more often active than composite volcanoes, some erupt near constantly for many decades. Composite volcanoes erupt far less often, and can be mistakenly thought of as being extint for hundreds of years between eruptions. Composite volcanoes tend to have much more explosive eruptions than shield volcanoes, which tend to be more effusive in nature. Composite volcanoes are capable of pyroclastic flows (Mt St Helens) and huge eruptions which can entirely destroy the volcano (Pinatubo, Krakatoa). Shield volcanoes tend to only erupt in lava flows, which can create enormous shallow volcanoes (Mauna Loa, Olympus Mons)
What kind of volcanoes form mountains?
shield volcanoes
What do shield volcanoes form?
Lava
Are shield volcanoes hot spots?
Shield volcanoes are not hot spots but they are associated with them. However, such volcanoes can also form at rift zones.
What kind of volcanoes create islands?
Both shield volcanoes and stratovolcanoes can form islands.
Where do shield volcanoes form?
at hot spots(a place where volcanoes are very active)
What kind of valcaneo erupted to form Hawaii?
Shield volcanoes.
Do shield volcanoes form from ash cinders and bombs?
Yes
What types of volcanoes be found in the Hawaii islands?
An underwater volcano. The volcano that made Hawaii was a shield volcano.
Do shield volcanoes form at hot spots?
Yes I am pretty sure.
Shield volcanoes form from the build-up of?
Fluid, basaltic lavas
What type of volcanoes form on a hot spot?
Shield volcanoes typically form on hot spots. These volcanoes have gentle slopes due to the low-viscosity basaltic lava they produce. Examples of shield volcanoes formed on hot spots include Mauna Loa in Hawaii and Galapagos Islands in Ecuador.
Does the lava that forms shield volcanoes probably have a lot of silica or water in it?
No. Shield volcanoes form from basaltic lava with a low silica content and a low water content.
