Question

How are volcanoes are classified? Explain

Answer 1

Answer:

Explanation:

Classification Of Volcanoes

When studying the volcanoes in the world it is important to understand what the classification of volcanoes is and how it works. There are several factors that go into account when attempting to classify a volcano into a group and that includes things like recent activity, periodicity of eruptions, size, potential impact and others. Though it is not common to hear it volcano eruptions are actually not that rare. More often than not the classification of volcanoes refers to the life cycle and that could define them as active, extinct or dormant. However, a volcano can also be classified by the composition of the structure and that would mean that it can be a shield, conical or stratovolcano. Finally they can also be classified because of its eruption which could be quiet or explosive.

Answer 2

There are three main types of volcano - composite or strato, shield and dome.

Composite Volcanoes

Composite volcanoes, sometimes known as strato volcanoes, are steep sided cones formed from layers of ash and [lava] flows. The eruptions from these volcanoes may be a pyroclastic flow rather than a flow of lava. A pyroclastic flow is a superheated mixture of hot steam, ash, rock and dust. A pyroclastic flow can travel down the side of a volcano at very high speeds with temperatures over 400 degrees celsius. Composite volcanoes can rise over 8000 feet.

A simple cross section through a composite volcano

When composite volcanoes erupt they are explosive and pose a threat to nearby life and property.

Eruptions are explosive due to the thick, highly viscous lava that is produced by composite cone volcanoes. This viscous lava has a lot to do with why they are shaped the way they are. The thick lava cannot travel far down the slope of the volcano before it cools.

Composite volcanoes are usually found at destructive plate margins.

Examples of composite volcanoes include Mount Fuji (Japan), Mount St Helens (USA) and Mount Pinatubo (Philippines).

Shield Volcanoes

Shield volcanoes are low with gently sloping sides and are formed from layers of lava. Eruptions are typically non-explosive. Shield volcanoes produce fast flowing fluid [lava] that can flow for many miles. Eruptions tend to be frequent but relatively gentle. Although these eruptions destroy property, death or injury to humans rarely occurs.

A simple cross section thr

ough a shield volcano

Shield volcanoes are usually found at constructive boundaries and sometimes at volcanic hotspots. Examples of shield volcanoes include Mount Kilauea and Maunaloa on Hawaii.

The video below shows a lava flow from Mount Kilauea.

Dome (Acid Lava Cones)

Acid [lava] is much thicker than [lava] which flows from shield volcanoes. Dome volcanoes have much steeper sides than shield volcanoes. This is because the lava is thick and sticky. It cannot flow very far before ot cools and hardens. An example is Puy de Dome in the Auvergne region of France which last erupted over 1 million years ago