By: Jaime
Volcano Records-
Copahue-Argentina
Chile
Location- 37.85S 71.17W
Guallatir, Chile
Location- 18.9S 69.2W
Lascar,
Chile
Location- 23.32S 67.44W
Coseguina,
Nicargua
Location- 12.59S 87.34W
Arenal,
Costa Rica
-About Volcanoes-
What is a Volcano?
A volcano is a weak spot in the earths crust where magma comes to the surface and turns into lava, and then cools to igneous rock.
Location of Volcanoes
Volcanoes occur in belts that extend across continents and oceans. A major volcano belt is the ring of fire. Most volcanoes occur along diverging plate boundaries, such as the mid ocean ridge, or in subduction zones around the edges of oceans. Subduction occurs where the edge of a continential plate collides with an oceanic.
Hot Spots
Some volcanoes result from "Hot Spots" in the earths mantle. A hot spot is an area where magma from deep within the mantle melts through the crust like a blowtorch. A hot spot volcano in the ocean floor can gradually form a series of volcanic mountains, for example, the Hawaiian Islands.
Types of volcanic eruptions
The silica content in magma helps determine whether a volcano is quiet or explosive.
Quiet eruptions-
Gas dissolved in the magma bubbles out gently. Thin runny lava oozes out quietly from the vent. Quiet eruptions produce two different kinds of lava: Pahoehoe and AA. Pahoehoe is fast moving hot lava. Lava that is cooler and slower is called AA.
Explosive Eruptions
If magma is thick and sticky and volcano erupts explosively. It slowly builds up in the volcanoes pipe, plugging it like a cork; the trapped gasses cannot escape from the thick magma. Then they explode, BOOM! and pyrodastic flow occurs when an explosive eruption hurls out ash.