Describe and explain the characteristic features of various types of volcanoes (8)

Describe and explain the characteristic features of various types of volcanoes (8) 

There are a variety of diverse volcano types which vary in characteristics. 

Composite volcanoes, sometimes called Strato cones, occur on destructive margins and are the classic pyramid-shaped volcanoes consisting of layers of ash from initial explosive phases of eruptions and subsequent layers of lava from the main eruption phases. The eruptions from these volcanoes may be from pyroclastic flows rather than a flow of lava. A pyroclastic flow is a super heated mixture of hot steam, ash, rock and dust. It can travel down the side of a volcano at very high speeds with temperatures over 400 degrees Celsius. The eruptions are fairly explosive due to the thick, highly viscous lava. An example of this is Mt. Pinatubo in the Philippines.

Secondly, there are shield volcanoes, which often occur at constructive plate boundaries, formed mostly from basaltic rock, which thus produce fast flowing (less viscous) lava that can flow for many miles, They are low lying, with gently sloping sides, with eruptions that are typically non-explosive, frequent, but relatively gentle. These eruptions can destroy property, however, due to how predictable they are, injury and death to humans is rare. They can sometimes be found at volcanic hot spots, including Mt, Kilauea in Hawaii.

A third type of volcano is a dome volcano (acid volcano), which are steep-sided, convex cones, consisting of viscous lava- which is mostly rhyolitc- very thick and sticky, which does not usually flow far, before t cools and hardens. An example of this is Puy de Done in the Auvergne region of France, which last erupted over a million years ago.

Another type of volcano is caldera, which forms when the build-up of gases beneath a blocked volcano vent becomes extreme and a huge explosion removes the summit of the cone, leaving an opening several kilometres in diameter. Calderas volcanoes, such as Krakatoa in Indonesia have large, deep openings, filled with water. Calderas have steep slopes due to rhyolitic lava- which is erupted from them. They frequently emit smoke and ash, but erupt irregularly and violently, due to how viscous they are.

Comments from sir: If you can revise all of this within the time allocated, then you have nailed it. Well done. 8/8
Characteristic features are common to all and must be mentioned: shape, ferocity, viscosity etc.