Volcanoes


Introduction :

I am going to talk about one of the worst natural disasters , volcnoes, which form when hot material from below rises and leaks into the crust. This hot material, called magma, comes either from a melt of subducted crustal material or it may come from deeper in the interior of a planet.


Where are volcanoes found?

Two thirds of the world’s active volcanoes are found along the "Ring of Fire" circling the North Pacific affecting areas like the west coast of North and South America , eatern islands of Australia and the east coast of Asia . you can observe this in this picture.



Types of volcanoes :

there are several different kinds of volcanoes: shield volcanoes , Cinder cones and composite volcanoes .

shield volcanoes are tall and broad, with flat, rounded shapes and they can grow to be very big. In fact, the oldest continental regions of Earth may be the remains of ancient shield volcanoes .

Mauna Loa, the largest of the shield volcanoes, is 13,677 feet above sea level, which means it rises over 28,000 feet above the deep ocean floor, and would be the worlds tallest mountain if much of it were not underwater.

Famous shield volcanoes include Mauna Loa, Kilauea, (two of the world's most active volcanoes)

Cinder cones are simple volcanoes which have a bowl-shaped They usually are created of eruptions from a single opening, unlike a shield volcano which can erupt from many different openings.

Famous cinder cones include Paricutin in Mexico.

The most majestic of the volcanoes are composite volcanoes, also known as strato-volcanoes. Unlike the shield volcanoes which are flat and broad, composite volcanoes are tall, symmetrically shaped, with steep sides, sometimes rising 10,000 feet high.

Famous composite volcanoes include Mount Fuji in Japan, Mount Shasta in Californiaand Mount Hood in Oregon .


The worst volcano disasters :

The worst volcano disaster was that of Tambora in 1815, which killed somewhere between 40,000 and 90,000 people (mostly from famine and disease after the eruption).


Conclusion :

Actullay we live in dynamtic planet which has many strange things , for example my topic Volcanoes which are known for their violent eruptions and lava flows, but there are many benefits that volcanoes provide for society. Volcanoes help enrich soil for farming and in some cases provide reservoirs for the storage of ground water . Moreover the earth's valuable resources are formed in volcanoes. These elements include sulfur, zinc and copper. Volcanoes even help us understand past civilizations and cultures .