Physical Geology & Plate Tectonics

Geology (study of Earth) is important for energy and natural resources, solving environmental problems, building cities and highways, predicting and protecting against natural disasters like earthquakes, volcanic eruptions, landslides, floods Uniformitarianism: fundamental principle “the present is the key to the past” How long? geologic time is measured in billions of years Where and How? After…

Where are Active Volcanoes?

Volcanoes formed at certian locations because they were along plate boundaries, which provide the ideal circumstances for magma formation and its subsequent eruption. At subduction boundaries the lithopsheres collide and the denser plate is pulled down into the mantle. This introduces water into the asthenosphere which lowers melting temperature and allows the less dense magma…