Volcanoes
A volcano is an area of Earth's surface through which magma and volcanic gases pass. During an eruption, magma is forced to the Earth's surface,but when it flows out of the volcanoes crater, which is the topmost circular hole of the volcano, it is called lava. Magma is molten rock. There are two types of volcanic eruptions, explosive and nonexplosive. Nonexplosive eruptions are the most common type of eruption. They have calm flows of lava, but can release hug amounts of it. Large areas are covered with these types of volcanoes, erupting all the time. Explosive eruptions are more rare than nonexplosive eruptions, however the effects of this type of volcano can be very destructive. Throughout the explosion, clouds of hot debris, ash, and gas are constantly shoot out from the volcano. Explosive eruptions cause molten rock to be blown into tiny particles that harden into the air. This type of eruption can blast millions of tons of lava and rock from the volcano. These volcanoes are so destructive, in seconds a volcano can wipe out the whole mountain. At the bottom of a volcano there is the magma chamber, which is the body of molten rock deep underground that feeds the volcano. Magma goes upward from the magma chamber and through the cracks in the earth's crust openings called vents. Magma erupts from a volcano in lava or pyroclastic material. Pyroclastic material is when magma is blasted into the air and hardens. There are four types of lava: Aa lava, Pahoehoe lava, Pillow lava, and Blocky lava. There are four types of pyroclastic material: volcanic ass, volcanic bombs, volcanic blocks, and Lapilli. Volcanic eruptions can make dramatic climate changes and make the sky dark. As volcanic ash and gases spread throughout the atmosphere, they can block enough sun light to cause global temperatures to drop. There are three types of volcanoes: shield, cinder cone, and composite volcanoes. Shield volcanoes are made out of layers of lava released from repeated nonexplosive eruptions. These volcanoes have gently sloping sides and spread over a wide area. The cinder cone volcano s made of pyroclastic material. Cinder cone volcanoes have steep slopes and are small, erupting for a short amount of time. They occur in clusters and erode quickly because the pyroclastic material is not cemented together. Composite volcanoes are also known as Stratovolcanoes and are the most common type of volcano. They are formed from explosive eruptions of pyroclastic material that is followed by flows of lava. Composite volcanoes have steep sides and broad bases that get steeper toward the top of the volcano. Volcanoes can make fertile soil, but can also do great destruction.
This is a Shield volcano.
This is a Cinder Cone volcano.
This is a Composite volcano.
This is Aa lava.
This is Pillow lava.
This is Pahoehoe lava.
This is Blocky lava.