بليز سااعدووني

A volcano is an opening in the Earth’s surface that enables the escape of magma, hot molten rocks, from under the surface. Over a long period of time, the volcanic activity tends to form hills or mountain-like features. Volcanoes release molten rock, ash, and poisonous gases which result from the melting in the mantle or in the crust layer of Earth.
There are various types of volcanoes such as shield volcano, composite volcano, cinder cones and seamount.
Shield volcanoes are some of the largest volcanoes. These are almost entirely of fluid lava flows. Mauna Loa, in Hawaii, is a shield volcano.
Some of the Earth's grandest mountains are composite volcanoes. They are typically steep-sided, symmetrical cones of large dimension built of alternating layers of lava flows, volcanic ash, cinders, blocks, and bombs and may rise as much as 8,000 feet above their bases.
Cinder cones are the simplest type of volcano. They are built from particles and blobs of congealed lava ejected from a single vent.