Volcanoes: Vesuvius Etna Thira Kilauea Mt StHellen Earth quake: he strongest earthquake ever recorded was a 9.5 on the Richter scale, occurring on the Peru-Chile Trench subduction zone west, offshore Chile, May 22, 1960. The small island town of Valdivia was closest and thus most affected, while the capital of the Araucan?a Region, Temuco, was the closest major city to the epicenter. *All* of the largest earthquakes occur along subduction zones, because that is where the most stress energy can be stored before the rock finally ruptures. More stored energy leads to greater seismic energy and shaking. The deep subduction of cold crust relative to the upper, warmer crust creates a brittle area, under a differential pressure of push-pull action between subducting plate, overriding plate, and the area of mantle that kind of gets awkwardly shoved between. It should make sense that you get more energy here at these subduction zones (convergent zones) where things are being slammed together, than whet you get at transform boundaries, like the famous San Andreas. The San Andreas will have many more earthquakes, but generally moderate at best. Subduction zones? Relatively rare, but can be absolutely huge, especially if you have a "megathrust" event, which can also create a massive tsunami, which is just as, if not more devastating than the earthquake. This is exactly what happened along the Java Trench in 2004, with the Sumatra ("Christmas Day") earthquake and Indian Ocean tsunami.