GEOL 1001 Chapter : Chapter 5 Geol 1
Document Summary
Volcano: an erupting vent through which molten rock surfaces, a mountain built from magmatic eruptions: volcanoes are caused by tectonic activity, volcanoes pose a number of hazards to humans. Volcanic eruptions: volcanic eruptions transfer materials from inside the earth to the planet"s surface. Forms of eruptions: lava flows = molten rock that moves over the ground, pyroclastic debris = fragments blown out of a volcano, volcanic gases = vapor and aerosols that exit a volcano. Lava flows: can be thin and runny or thick and sticky. Flow style depends on viscosity: composition: especially silica (sio2), fe, and mg content, temperature, Basaltic (mafic) lava: very hot, low silica, and low viscosity, basalt flows are often thin and fluid. It can travel so far because: rapid cooling of the surface of lava flow occurs as it emerges to the surface creating a cooled crust.
