GLG 111 Lecture Notes - Lecture 2: Wavefront, Seismometer, Lithosphere
Document Summary
Volcanoes can provide clues about the interior of rocks due to exploding magma. Oceanic crust is present in mountain regions. The crusts of oceans and continents differ in both composition and thickness. Continental crust contains mostly quartz-bearing igneous and metamorphic rocks with an average composition of diorite to tonalite which is about greater than 25 kilometers thick. Oceanic crust consists of mafic igneous rocks and is about 7 kilometers thick. Both types of crust rest on peridotite mantle. Waves-disruptions that move through a medium, such as rock, air, or in this case, water, without any overall transport of the medium in the direction that the waves move. Elastic-waves that do not permanently deform the water. Plastic-waves that permanently deform the water when you let go. Earthquake-instantaneous release of stored energy resulting from the breaking and sudden movement of rock under stress.
