science
Consists of fragments of rocks, minerals, and volcanic glass created during volcanic eruptions
ash
A funnel-shaped opening at the top of a volcano
crater
Molten rocks beneath the volcano
magma
Magma that flows out of the earth's surface
lava
Tunnel-like inside a volcano where magma travels to reach the earth's surface
main vent
is a vent, hill or mountain from which molten or hot rocks with gaseous material have been ejected: craters, depressions, hills or mountains formed from the ejected materials accumulated on the earth's surface
volcano
is a volcano that has a record
of eruption within the last 600 years or has erupted 10,000 years ago based on analyses of its materials
active volcano
is the one that has no record of eruption for the last 10,000 years and its physical form is being changed by agents of weathering and erosion through formation of deep and long gullies.
inactive volcano
opening which may either be a crater or a caldera.
summit
is a funnel-shaped opening at the top of a volcano.
crater
is formed when a part of the wall collapses following an explosive eruption.
caldera
are formed from the accumulation of lava that oozes out
from the volcano. Since non-viscous lava can flow freely, a broad, slightly domed structure that resembles a warrior's shield is formed. An example of this type is the Mauna Loa Volcanc in Hawaii.
shield volcani
are built
- from ejected lava fragments. They have steep slope, wide crater and are the most abundant of the three major volcano types. One example of this type is the Paricutin Volcano in Mexico.
cinder cones
or
stratovolcanoes are large, nearly perfect sloped
structure formed from alternate solidification of both lava and pyroclastic deposits. One perfect example of this type of cone is ou Mayon Volcano.
composite cone
-Eruptions depend on the following factors:
1. magma's temperature
2. chemical composition (which is mainly SiO2)
3. amount of dissolved gases they contain.
is the property of the material's resistance to flow. It is also described as the liquid's thickness and stickiness. The more viscous and thicker the material is, the greater is its resistance to flow
viscosity
It happens when the hot rocks come in contact with water. It is called a stream-driven eruption, short-lived, characterized by ash columns but may be the onset of a larger eruption. Bulusan volcano in Sorsogon displayed this kind of eruption.
1.Phreatic
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 pyroclastics called base surges are observed.
Phreatomagmatic
type of eruption was demonstrated by Irazu volcano in Costa Rica. Bursting of huge clots, lava from the volcano's summit crater was displayed forming a luminous arc from the sky. It is also described as a periodic weak to violent eruption characterized by fountain lava.
Strombolian-
is characterized by tall eruption columns that reach up to 20 km high with pyroclastic flow and ashfall tephra like that of Paricutin Volcano in Mexico
vulcanian
is considered as the most powerful and deadliest type of eruption. It ejects excessive amount of ashes and pyroclastics, together with an explosive explosion of viscous lava. This type of eruption was observed in Mt. Saint Helen in 1960 and Pinatubo volcano in Zambales, in 1991.
Plinian