Question

Which of the following is not included in the classes of volcanoes classified on the basis of the frequency of their eruption?
A) Active Volcanoes
B) Dormant Volcanoes
C) Extinct Volcanoes
D) Composite Volcanoes

Answer 1

Hint: A volcano is a break in the crust of a planetary-mass object, such as Earth, that allows volcanic ash, hot lava, and gas to escape from a magma chamber which is beneath the surface. On Earth, volcanoes are most commonly found in places where tectonic plates split. or converge, and most are underwater.

Complete answer:
Let us analyze the given options:
Option A) Active volcanoes erupt regularly. Examples of active volcanoes are Kilauea in Hawaii, Mount Etna in Italy, and Mount Stromboli also in Italy, which has been erupting almost constantly for 2000 years.
Option B) Dormant volcanoes are volcanoes that have not erupted in a long time but are likely to erupt again in the future. Examples of dormant volcanoes are Mount Kilimanjaro in Tanzania, Africa, and Mount Fuji in Japan.
Option C) Extinct volcanoes are the ones that have now no longer erupted in human history. Examples of extinct volcanoes are Mount Thielsen in Oregon withinside the US and Mount Slemish in Co. Antrim.
Option D) Composite cone volcanoes are also called stratovolcanoes. They arise when different types of eruptions deposit different materials on the slopes of a volcano. Alternating eruptions of volcanic ash and lava create layers. Over time, these layers build up. The result is a cone steeper than a cinder cone but steeper than a shield volcano. Mount St. Helens in Washington state is an example of a compound cone volcano.

Thus, the correct answer is an option (D) Composite volcanoes are not included in the volcanoes classified on the basis of the frequency of their eruption.

Note: The rock in the subducted plates melts into molten magma, which works its way to the surface and forms a magma chamber. The gases dissolved in the magma expand and cause a massive increase in pressure. This increased pressure causes the magma to rise and work its way through cracks/crevices in the volcano above. When it reaches the surface, pressure is released and an eruption occurs. During an eruption, volcanic ash, rock particles, dust, gases, and lava are emitted.