Natural Disasters – Volcanic Eruption

Volcanic Eruption happens when the molten rock from inside the Earth flows into the surface.
Volcanic Eruption is caused by the Earth’s internal heat, and is associated with tectonic processes and is a part of the rock cycle.

A volcano is a vent through which molten magma and gases are discharged to the surface.
Volcanos can be formed when the rock near the surface becomes hot enough to melt.
This often happens in in locations which are also plate boundaries.
In a divergent boundary, such as at mid-ocean volcanic ridges, material from Earth’s interior slowly rises up, melts when it reaches lower pressures, and fills in the gap.
Chambers of magma may form in places where one plate is being subducted under another.
These magma bodies feed the volcanic islands which help mark the locations of subduction zones.

The presence of volcanos on Earth tells us that Earth’s interior is circulating and is hot enough to melt rocks.
Earth is constantly cooling and volcanos are one way to lose heat.
The pattern of distribution of volcanos on Earth gives us a clue into the is divided into plates on Earth’s outer surface.
The chains of volcanos associated with mid-ocean ridges and subduction zones mark the edges of tectonic plates.

These are not very steep but are far and wider and extend to great height as well as distance.
Lava erupts commonly from vents along fractures aka rift zones, that develop along the flanks of the cone.
These volcanoes are made up of basaltic rocks which are less viscous and is very fluid during eruption.
They are generally not very explosive, but may turn explosive if water gets into the vent somehow.

These are small volcanoes formed by loose, grainy cinders which are extrusive igneous rocks and almost no lava.
Cinder cones are the simplest type of volcano and have very steep sides and usually have a small crater on top.

They are cone shaped with moderately steep sides and having small craters in their summits.
They are characterized by the eruption of a cooler and more viscous lava than basaltic volcanoes.
The deterministic feature of a composite volcano is the presence of a conduit system through which magma from a reservoir deep in the Earth’s crust rises to the surface.
The material accumulates in the vicinity of the vent openings which leads to the formation of layers, and this gives them their alternate name as stratovolcanoes.

They are the most explosive type of volcanoes on Earth.
Their eruptions result in them collapsing on themselves rather than building any tall structure.
They gained their name from these collapsed depressions which are also called as calderas.

Natural Disasters-Volcanic Eruption