Lesson 1 Volcano Flashcards
What is a volcano
Refers to a mountain or a hill, typically conical, having a crater or vent, which lava, rock fragments and hot vapor or have erupted from the Earth’s crust.
Summit
is the highest point or the apex of the volcano. At the summit, you have an opening called a vent.
Slopes
are the sides or flanks of a volcano that radiate from the main or central vent.
Base
is lower outer part of the volcano.
Magma Chamber
is a region beneath the vent of a volcano where molten rock or magma is deposited or stored before eruption.
Main Vent
is the main opening or outlet on the surface of a volcano that emits lava, gases, ash or other volcanic materials.
Conduit
is an underground central tube-like or pipe-like structure of a volcano that connects the magma chamber to the crater through which the magma travels.
Side Vent
is a smaller outlet through which magma escapes.
Crater
is the mouth of the volcano which is a funnel-shaped or bowlshaped hollow at the top of the vent from where magma, ash and gas comes out.
Lava
is a molten rock which is given off onto the surface of the Earth when a volcano erupts.
Ash and Gas Cloud
is a mixture of rock, minerals, glass particles and gases expelled or pushed out of the volcano during volcanic eruption.
Cinder cone volcanoes
are the simplest type of volcano. They are built from particles and blobs of solidified lava ejected from a single vent. Lava is thrown into the air, which breaks into small fragments that solidify and fall as cinders around the vent to form a circular or oval cone.
An example of a cinder cone is
Philippines are Taal Volcano in Batangas, smith volcano found in Babuyan Group of islands, Mount Mayabobo found in Quezon Province, and Mount Musuan in Bukidnon. An example of this outside of the Philippines is the Paricutin volcano in Mexico.
Composite volcanoes or stratovolcanoes
are large, typically steepsided, symmetrical cones of large dimension formed from alternating layers of lava flows, volcanic ash, cinders, blocks, and pyroclastic materials. One important feature of a composite volcano is the conduit system from which magma rises to the surface of the Earth. They are formed from viscous, or sticky, lava that does not flow easily. The lava builds up around the vent Composite Volcano forming a volcano with steep sides.
Example of stratovolcano
Mount Mayon in Albay, Mount Arayat in Pampanga, Mount Kanlaon in Negros Island, and Mount Apo in Davao Region. An example of these outside the Philippines are Mount Rainier in Washington, USA, and Mount Fuji in Japan.
Shield volcanoes
Shield volcanoes are large, broad volcanoes that look similar to shields from above – hence the name. These volcanoes are built almost entirely of fluid lava flow thus these volcanoes Shield Volcano are not steep. They can be easily identified because they are tall and broad, with flat, rounded shapes. The lava is not accompanied by pyroclastic materials, which makes shield volcanoes relatively safe. Eruptions at shield volcanoes are only explosive if water somehow gets to the vent
An example of shield volcano
Mauna Loa in hawaii
Phreatic or Hydrothermal
is a violent eruption due to the contact between water and magma. As a result, a large column of very fine ash and high-speed and sideway emission of pyroclastic materials called base surges are observed.
Strombolian
periodic, weak to violent eruption characterized by fountain lava, just like the Irazu Volcano in Costa Rica.
Vulcanian
is characterized by tall eruption columns that reach up to 20 km high with pyroclastic flow and ash fall tephra like that of Paricutin Volcano in Mexico.
Plinian
excessively explosive type of eruption of gas and pyroclastic materials, like in Pinatubo Volcano in Zambales.
