There are three places a volcano can occur: at mid-ocean ridges, at subduction zones where a continental and ocean plate collide, and at a hot spot located in the middle of a plate. Mid-ocean ridges are caused by divergent tectonic plates and are the most volcanically active feature on earth.Continue Reading
Subduction zones occur when an oceanic plate and a continental plate collide, which causes the denser oceanic plate to slide underneath the lighter continental plate. When this happens, the crust in the oceanic plate is pulled deeper into the earth, where it eventually melts to form magma that eventually rises to the surface through the volcano. The "Pacific Ring of Fire" that stretches around the Pacific is home to the majority of the world's subduction zones, which is why it is also home to most of the land volcanoes on earth.
The third type of volcano occurs at a so-called hot spot, which is a thinner spot in the earth's crust where magma rises to the surface to form a volcano. Most volcanoes that result from hot spots have more gradual, less destructive eruptions. The Hawaiian Islands were formed by such a hot spot, with each separate island being formed over time as the oceanic plate slid over the top of the hot spot.Learn more about Volcanoes
The name for volcanoes forming at hot spots is seamount: these volcanoes form along ridges on sea floors, and may rise high above the sea's surface, creating islands. Seamounts span among the greatest distances of all landforms on Earth, according to National Geographic. They cover vast stretches of land, generally protruding upwards from ocean crusts, although they sometimes appear beneath continents too.Full Answer >
The plate tectonics theory suggests that the outer shell of the Earth's surface is split into a few plates that move along the mantle, forming a hard shell, with pressure from mid-ocean ridges and subduction zones causing the shifting in the plates. Mid-ocean ridges are the gaps that lie between the plates, much like the seams on a basketball. Magma oozes through these ridges, creating new crust on the ocean floor and pushing the plates apart, while subduction zones sit at the meeting point between plates. One slides under the other, pulling the crust down as it goes.Full Answer >
Cinder-cone volcanoes, properly called scoria volcanoes, erupt when expanding gas bubbles drive lava to the volcano's surface. Because of this pressure, the lava fountains are usually very high and vertical. By the time the erupted material lands, it is already cool.Full Answer >
A Cascade Range volcano is one that is part of a series of mountains in western North America that includes an arc of volcanoes. The Cascade Range extends from British Columbia through Washington and Oregon to northern California.Full Answer >