Chapter 5: Magma And Volcanoes
Chapter 5: Magma And Volcanoes
Introduction: Earth's Internal- Thermal Engine ■ Magma is molten rock beneath Earth’ s surface Because liquid magma is less dense than surrounding solid rock, and obviously more mobile, magma, once formed, rises toward the surface a Magma that reaches the surface does so by erupting through vents we call volcanoes
Introduction: Earth’s Internal-- Thermal Engine ◼ Magma is molten rock beneath Earth’s surface. ◼ Because liquid magma is less dense than surrounding solid rock, and obviously more mobile, magma, once formed, rises toward the surface. ◼ Magma that reaches the surface does so by erupting through vents we call volcanoes
Volcanoes a The term volcano comes from the name of the Roman god of fire, Vulcan There are different types of volcanoes. Eruption vary from gentle flows(Hawaii and Iceland) to catastrophic explosions(Mount St Helens, Mt Pinatubo, Soufriere Hills) The majority of eruption never make the news because they occur beneath the ocean, unobserved
Volcanoes ◼ The term volcano comes from the name of the Roman god of fire, Vulcan. ◼ There are different types of volcanoes. ◼ Eruption vary from gentle flows (Hawaii and Iceland) to catastrophic explosions (Mount St. Helens, Mt. Pinatubo, Soufriere Hills). ◼ The majority of eruption never make the news because they occur beneath the ocean, unobserved
Magma a Magma has a wide range of compositions, but silica(SiO2)always dominates the mix. Magma has high temperatures. Magma is fluid--it has the ability to flow a Most magma actually is a mixture of liquid (often referred to as melt) and solid mineral grains
Magma ◼ Magma has a wide range of compositions, but silica (SiO2) always dominates the mix. ◼ Magma has high temperatures. ◼ Magma is fluid—it has the ability to flow. ◼ Most magma actually is a mixture of liquid (often referred to as melt) and solid mineral grains
Composition of Magmas and Lavas The composition of magmas and lavas is controlled by the most abundant elements in the Earth-Si, Al, Fe, Ca, Mg, Na, K, H, and o. Three distinct types of magma are more common than others: Basaltic, containing about 50 percent SiO2 Andesitic, about 60 percent SiO2 Rhyolitic, about 70 percent Sio
Composition of Magmas and Lavas ◼ The composition of magmas and lavas is controlled by the most abundant elements in the Earth—Si, Al, Fe, Ca, Mg, Na, K, H, and O. ◼ Three distinct types of magma are more common than others: ◼ Basaltic, containing about 50 percent SiO2. ◼ Andesitic, about 60 percent SiO2. ◼ Rhyolitic, about 70 percent SiO2