An illustrated introduction to the earth’s tectonic plates, their relative movements and the resultant earthquakes, volcanic eruptions and potential tsunami. The basic structure of the earth and the seismological evidence used to define it will be described. Areas of particular interest include the Mid-Atlantic Ridge, Iceland, the East Africa Rift Zone, the Himalayas, Indonesia, Hawaii, the San Andreas Fault system and the Cascadia subduction zone. Recent major earthquakes such as those in Sumatra, Haiti, Chile, Japan, Nepal and California and major eruptions in Chile and Peru, the Philippines, Sumatra, the Caribbean and the Cascades will be examined. We will also look at the geological danger areas of the continental United States.