Why Do People Live Near Subduction Zones

Subduction zones are the most tectonically active places on Earth.  Most of the volcanoes, large earthquakes, and mountain building processes active today, occur at these sites.  Subduction zones are dangerous places, however many people live near them.  Some of the reasons may be due to following: (1) Many important natural resources are derived from subduction processes, such as highly fertile soils, copper, gold, silver, and zinc. Lecture 19 discusses how subduction zones “end up being factories for concentrating mineral and metal ore natural resources,” and that it would be very difficult to build anything like a building or city without the existence of subduction zones. The example given was of how the gold rushes in America were both located at former subduction zones: California and the Yukon; (2) Also, ocean trade has always been a major function in both ancient and modern societies, and therefore civilization and cities would have been built around these seaports; (3) Ocean life, such as mussels, crabs and shrimp, would be abundant around volcanic island arcs, due to the warm mineral-rich water, and therefore a source of revenue; (4) These locations by the water or on the shoreline are very scenic, and are often sought after real-estate; and (5) Most critically, I think that because the understanding of subduction zones, and plate tectonics in general, is relatively very new, many of the populations located in these areas were probably, in some cases, centuries old, and well established. Basically they were already there before we understood the subduction process.  (Wegener’s concept of continental drift was only proposed in 1912, and plate tectonics, not until the 1950’s and 60’s).