An Introduction to Convergent Margins and Their Natural Hazards

This chapter presents three great natural hazards: earthquakes, volcanic eruptions, and tsunamis. These three natural hazards pose increasing risks as economic activity and population continues to grow around the Pacific and eastern Indian Oceans, which are surrounded by convergent plate margins. The concept of convergent plate margin is similar to the concept of a convergent plate boundary except that the former encompasses broader regions on either side of the boundary itself. These are generally associated with subduction zones and pose a severe risk to nearby human populations. The chapter outlines basic plate tectonic concepts, and the most important features of convergent plate margins and subduction zones. The most spectacular surficial manifestations of a convergent margin are the trenches, which mark the plate boundary and where the greatest depths in any ocean are found. Another distinctive feature of most convergent plate margins is a chain of great volcanoes, parallel to and set back from the trench.