Volcanic Eruptions Subtitle Inside the Volcano Magma Chamber

Volcanic Eruptions Subtitle

Inside the Volcano ▪ Magma Chamber : an underground pool of magma ▪ Pipe: a long tube that connects the magma chamber to the Earth’s surface ▪ Vent: the opening that magma and gases flow through at the Earth’s surface ▪ Lava flow: an area on the Earth’s surface that is covered by lava ▪ Crater: a bowl shaped area that forms around the vent

Inside a Volcano

What causes a volcanic eruption? ▪ Dissolved gases in the magma expand creating pressure ▪ Magma rises to the surface ▪ As pressure builds from expanding gases magma fills the pipe ▪ Magma can flow or explode from a vent

Types of Eruptions Quiet Explosive ▪ Low silica…. low sticky…low viscosity ▪ High silica…. highly sticky…. high viscosity ▪ Magma flows slowly for many kilometers ▪ Pipe gets clogged and the pressure builds up ▪ Rock fragments are released

Pyroclastic flow: ejected from a volcano a mixture of rock fragments ▪ Volcanic ash: is the smallest rock fragments the size of dust ▪ Cinders: are pebble sized rock fragments ▪ Bombs: are larger pieces of rock

Fast Cooling Lava from Highly Silica Eruptions Pumice Obsidian ▪ a very light and porous volcanic rock formed when a gas-rich froth of glassy lava solidifies rapidly. ▪ Smooth, glassy rock

Volcanic Hazards ▪ Deadly gases can asphyxiate people ▪ Volcanic ash, if breathed in, creates a cement mixture in your lungs ▪ Volcanic ash is heavy, so it can cause roofs to collapse ▪ Volcanic ash can damage engines…. cars and planes ▪ Creates landslides, mudslides, and avalanches

Stages of a Volcano ▪ Active: volcano that has had at least one eruption during the past 10, 000 years. An active volcano might be erupting or dormant. ▪ Erupting (live): active volcano that is having an eruption ▪ Dormant (sleeping): active volcano that is not erupting, but supposed to erupt again. ▪ Extinct (dead): a volcano that has not had an eruption for at least 10, 000 years and is not expected to erupt again in a comparable time scale of the future.