Chapter 2: Earthquake hazard

The chapter is intended to give structural engineers unfamiliar with engineering seismology sufficient background on ground motion issues to inform their structural designs, and to give references to further sources of information. It covers

Much of the earth’s seismic activity is concentrated into two active zones (Figure 2.1). These are the Ring of Fire around the edge of the Pacific Ocean and the broad Alpide belt, which stretches across the Mediterranean and southern Europe to the Himalayas and into eastern China. Between them, these two areas account for approximately 97% of the world’s largest earthquakes (80% in the Ring of Fire and 17% in the Alpide belt). These two belts, and the other areas of high seismic activity around the world, occur along the junctions between the tectonic plates, which together form the strong but brittle outer skin of the earth called the lithosphere.