What is a lava flow simple definition?
Lava flows are streams of molten rock that pour or ooze from an erupting vent. Lava is erupted during either nonexplosive activity or explosive lava fountains.
What is a viscous lava flow?
Viscous lava will trap pockets of gas within the rock, and not let them pop as bubbles on the surface. But most importantly, highly viscous lava is associated with explosive eruptions and dangerous pyroclastic flows. An example of a low viscosity (fast flowing) lava is basaltic lava.
What are the 3 types of lava flow?
Lava erupting on the deep sea floor has a form most like pahoehoe flows. Threetypes of lava flows are common on the sea floor: pillow lava, lobate lava, andsheet lava.
What is the flow of lava called?
‘A’a lava flows are also called clinkers, because of their rough and jagged appearance. The eruptions of submarine volcanoes result in pillow lavas, which form as the lava cools in seawater.
What are the two types of lava flow?
Lavas, particularly basaltic ones, come in two primary types: pahoehoe (pronounced ‘paw-hoey-hoey”) and aa (pronounced “ah-ah”). Both names, like a number of volcanological terms, are of Hawaiian origin. A third type, pillow lava, forms during submarine eruptions.
How does lava flow?
Lava forms when magma erupts from a volcano. As pressure is released gases, dissolved in the magma, bubble out so the composition of lava changes. Most lava flows are formed by the eruption of hot (around 1200oC) basalt magma, (see video clip above).
Why is lava viscous?
The cooler the lava, the higher the viscosity (the thicker it is). Composition: he more felsic the lava (the more silica in the lava), the higher the viscosity because silica forms chains in the cooling lava even before it crystallizes. The more mafic the lava (the less silica in it), the lower the viscosity.
What are 4 types of lava?
Because of the role of silica in determining viscosity and because many other properties of a lava (such as its temperature) are observed to correlate with silica content, silicate lavas are divided into four chemical types based on silica content: felsic, intermediate, mafic, and ultramafic.
What are the two types of lava flows?
Lavas, particularly basaltic ones, come in two primary types: pahoehoe (pronounced ‘paw-hoey-hoey”) and aa (pronounced “ah-ah”).
What is fast flowing lava called?
Discern the difference between pahoehoe and aa volcanic lava flows at Kilauea, Hawaii. Lava flowing toward the sea from Kilauea volcano, Hawaii, takes two recognizable forms: fast-flowing, ropy lava, called pahoehoe, and thick, blocky lava, called aa.