Man and Volcanoes: The Benefits

Abstract

Early traces humans left in East Africa about 3 million years ago are footprints in volcanic tuffs (Fig. 15.1). It is as if man had walked through a thin layer of freshly poured-out concrete that subsequently hardened to the benefit of posterity and anthropology. Seen in historical perspective, volcanoes are a threat to people, commonly only for very brief periods. Exceptions are places, such as the city of Kagoshima on the southern tip of the Japanese island of Kyushu, with its almost daily rain of ashes from the nearby almost permanently active volcano Sakurajima. The custom to dry clothes in the garden thus never developed in Kagoshima. In general, however, man has always benefited very much more from volcanoes than suffered from their eruptions. The undeniable benefits of volcanoes range from obsidian tools used in many early cultures, caves that can be dug easily in massive tuffs, fertile soils, attractive landscapes to geothermal energy. It is little known, for example, that a modern city such as San Francisco, receives the bulk of its electric energy from a young volcanic area, the Geysers, a couple of hours by car north of the Golden Gate metropolis.