We consider volcanoes, types of eruptions, and typical rocks found there. We will emphasize that plate tectonics-the grand unifying theory of geology-explains how the map of our planet's surface has changed radically over geologic time, and why present-day geologic activity-including a variety of devastating natural disasters such as earthquakes-occur where they do.
We begin with earthquakes-what they are, what causes them, what effects they have, and what we can do about them. Planet Earth presents an overview of several aspects of our home, from a geological perspective. Earthquakes, volcanoes, mountain building, ice ages, landslides, floods, life evolution, plate motions-all of these phenomena have interacted over the vast expanses of deep time to sculpt the dynamic planet that we live on today.
