TYPES OF VOLCANOES

Types of volcanoes

There are three main types of volcanoes

1. Active volcanoes which are currently or have recently erupted.
2. Dormant volcanoes which have not erupted recently and is expected to erupt at any time.
3.  Extinct volcanoes which has stopped to erupt and will never erupt again.

On earth, volcanism occurs in several distinct geologic settings.

The first place of volcanic activities are  those areas associated with the boundaries of the enormous rigid plates that make up the lithosphere (the crust and upper mantle). The majority of active terrestrial volcanoes (roughly 80 percent) and related phenomena occur where two lithospheric plates converge and one overrides the other, forcing it down into the mantle to be reabsorbed.

A second major site of active volcanism is along the axis of the oceanic ridge system, where the plates move apart on both sides of the ridge and magma wells up from the mantle, creating new ocean floor along the trailing edges of both plates. All of this volcanic activity occurs underwater. Iceland is the best example. The magma that are erupted along the oceanic ridges are basaltic in composition.