Day 13 – Q 3. Why do some volcanos become dormant while many remain active? Explain with the help of suitable examples.

21 Nov, 2018 Day 13, GS 1, World Geography 100 Comments 0

3. Why do some volcanos become dormant while many remain active? Explain with the help of suitable examples.

कुछ ज्वालामुखी निष्क्रिय क्यों रहते हैं जबकि कई सक्रिय रहते हैं? उपयुक्त उदाहरणों की मदद से समझाओ।

Introduction:

A volcano is an opening in the Earth’s crust that allows molten rock, gases, and debris to escape to the surface.

Body:

Volcanoes tend to exist along the edges between tectonic plates, massive rock slabs that make up Earth’s surface. About 90 percent of all volcanoes exist within the Ring of Fire along the edges of the Pacific Ocean.

Types of Volcanos:

Active Volcano.
Dormant Volcano.
Extinct Volcano.

About 1,900 volcanoes on Earth are considered active, meaning they show some level of activity and are likely to explode again. Many other volcanoes are dormant, showing no current signs of exploding but likely to become active at some point in the future.

Volcanoes go dormant because magma from the Earth’s mantle can no longer reach the volcano.
If a volcano doesn’t have a source of magma, it won’t erupt.
As the islands move away from the supply of magma, volcanoes become dormant.
They become dormant because the Earth’s plates are constantly shifting above volcanic hotspots.
Volcano can also become dormant if when the angle of subduction changes and magma begins to rise through the mantle in a different location.
The tectonic plate continues to shift above the hotspot, and eventually the volcano is shut off from the magma chamber beneath. The magma finds a new source to the surface, creating a new active volcano. The older volcano stops erupting and becomes dormant.

Examples of Dormant volcanoes: