Volcanoes What is a Volcano A volcano is

Volcanoes

What is a Volcano? • A volcano is an opening at the Earth’s surface. • Magma, gas and other materials erupt through the opening. • Lava releases from the main vent. • When the lava cools and produces new rocks high in minerals. • Volcanoes can be extinct, dormant or active. ØExtinct – will not erupt again ØDormant – has not erupted in the last 2000 years ØActive – has erupted recently.

Main features of a volcano

How do volcanoes erupt? • Many reasons why volcanoes erupt, but • There are three main reasons: ØBuoyancy of the magma – magma rises to the earth’s crust and erupts. ØPressure of the gases – the more gas in the magma creates an eruption. ØNew magma in the magma chamber – the new magma rises in the main vent and causes an eruption. • Volcanoes are very difficult to predict.

Six main types of Volcanoes on Earth. • Stratovolcanoes (Composite). • Shield Volcanoes • Cinder Cone • Lava Domes • Giant Caldera Volcano • Fissure Volcano

Stratovolcano (Composite) • Has steep sides made from lava, volcanic ash and cinders. • Eruptions may be a pyroclastic flow. • Pyroclastic flow is a combination of rock, ash, steam and dust. • Pyroclastic flow travel at very high speed down the volcano. • Pyroclastic flow temperature exceeds 400 degrees Celsius. • Composite volcanoes can be over 8, 000 feet high (2438. 3 meters). • They are very explosive and a concern for people and property. • Composite volcanoes include: Mount Fuji (Japan), Mount St. Helens and Mount Rainier (Washington). http: //www. cotf. edu/ete/modules/volcanoes/vtypesvolcan 1. html

Shield Volcano • Gentle sloping sides formed from lava. • Eruptions normally non-explosive. • Lava can flow over great distances. • They can have numerous eruptions but are gentle. • Can be 1, 500 to 2, 000 feet high. • Width of 3 or 4 miles. • Can destroy people’s possessions but death or injury is rare. • Can be some of the largest volcanoes in the world. • Shield Volcanoes include: Mount Kilauea and Maunaloa (Hawaii). http: //www. cotf. edu/ete/modules/volcanoes/vtypesvolcan 1. html

Cinder Cone Volcano • Simplest type of volcano • Build from lava components being released from the single vent. • The lava is blown into the air aggressively. • The lava creates a oval shaped cone. • Which then forms a bowl shaped crater at the top. • Cinder Cone volcanoes are about 1, 000 feet high. . • Cinder Cone volcanoes are in most parts of the world but common in North America. • Cinder Cone Volcanoes include: Tumble Buttes, Twin Buttes (California), Ankaizina Feild (Madagascar) and Altlin Valc Feild (Canada). http: //www. cotf. edu/ete/modules/volcanoes/vtypesvolcan 1. html

Dome Volcano • Lava from a Dome Volcano is thicker than lava from a Shield Volcano. • Has steeper sides than a Shield Volcano. • Lava is think and sticky. • Lava cools and hardens quickly so does flow far. • The lava forms around and over the vent. • Eruptions can be destructive. • Dome Volcanoes include: Mount Semeru (Indonesia), Augustine (Alaska) and Barawli (Ethiopia). http: //www. explorevolcanoes. com/Lava%20 Dome. html

Caldera Volcano • Most powerful and tragic volcano. • They are an inverse shaped volcano. • The magma chamber increases size under the ground and forms extreme pressure of gas. • Once the pressure has been released through pyroclastic eruptions, the magma chamber caves in. • Largest on earth measuring a width from 15 - 100 metres. • Caldera Volcanoes include: Toba Eruption (Indonesia), The Yellowstone Caldera in (Wyoming, USA). http: //www. cotf. edu/ete/modules/volcanoes/vtypesvolcan 2. html

Fissure Volcano • No dominate crater. • Fissure volcanoes are only a few metres wide but are kilometres in length. • Giant cracks in the ground which releases lava to extreme distances. • When the lava cools ad hardens, the surface remains flat. • Volcano cracks are buried and difficult to see evidence of a volcano. • Fissure Volcanoes include Los Pilas (Nicaragua), Banda Api volcano (Indonesia) and Krafla volcano (Iceland). http: //www. cotf. edu/ete/modules/volcanoes/vtypesvolcan 2. html

Volcano on Titan • May have cryovolcanoes (ice volcanoes) on Saturn. • They erupts icy liquids such as water, ammonia and hydrocarbons instead of lava. • Can be as high as 1 500 meters and have a depth of 1 500 meters. http: //www. bbc. com/earth/story/20150708 -the-volcanoes-found-in-space

Volcano on Mars • Mars used to have the biggest and best volcanoes in. • The Olympus Mons (pictured) is the biggest volcano in the solar system. • It is 25 kilometres tall and has a width of 624 kilometres. • It is extinct because it has not erupted for millions of years. http: //www. bbc. com/earth/story/20150708 -the-volcanoes-found-in-space

Volcanoes on lo • Lo is one of the large moons on Juniper. • Lo is covered in active volcanoes. • Lo erupts clouds of sulphurous chemicals. • Volcanoes erupt on lo because the interior is very hot. http: //www. bbc. com/earth/story/20150708 -the-volcanoes-found-in-space

Similarities and differences of a volcano on Earth and on Titan.

References BBC. (2015). All the planets and moons known to have volcanoes. Retrieved from http: //www. bbc. com/earth/story/20150708 -the-volcanoes-found-in-space Bioexpedition. (2013). Fissure Vent Volcano. Retrieved from http: //www. basicplanet. com/fissure-vent-volcano/ Extreme Science. (2015). Caldera Volcanoes. Retrieved from http: //www. extremescience. com/calderas. htm Fact Monster. (2013). Types of Volcanoes. Retrieved from http: //www. factmonster. com/ipka/A 0862596. html Internet Geography. (2015). What is a volcano? Retrieved from http: //www. geography. learnontheinternet. co. uk/topics/whatvolcano. html#volint Kilinc, A. (1999). What causes a volcano to erupt and how do scientists predict eruptions? Retrieved from http: //www. scientificamerican. com/article/what-causes-a-volcano-to/ Wall, M. (2010). Ice Volcano Found on Saturn Moon Titan. Retrieved from http: //www. space. com/10486 -ice-volcano-saturnmoon-titan. html Wheeling Jesuit University. (2004). Exploring the Environment Volcanoes. Retrieved from http: //www. cotf. edu/ete/modules/volcanoes/vtypesvolcan 1. html