Active Volcanoes Of Chiapas Mexico El Chich N And Tacan

This publication summarizes the studies carried out at two of the most active volcanoes of Chiapas (Mexico): El Chichón and Tacaná. El Chichón erupted explosively in 1982 killing more than 2000 people being the worst volcanic disaster in Mexico, and Tacaná produced two mild phreatic explosions in 1950 and 1986. Only after these explosions a surge of new studies began to unreveal their volcanic history and impact. This book presents the state of the art advances in topics related to the geologic setting of the two volcanoes, their eruptive history and composition of erupted products, the hydrothermal systems and their manifestations. Volcanic hazards and risks and possible mitigation plans are discussed based on the experience of the catastrophic eruption of El Chichón that occurred in 1982. The book will also include previously unpublished material on the flora and the fauna of the region and archaeological and social aspects of the area that is inhabited by indigenous people.

For many centuries people living on volcanoes have known that the outset of seismic activity is often a forerunner of a volcanic eruption. This understand ing allowed people living close to the sites of the Mt. Nuovo 1538 eruption at Campi Flegrei, Italy, and of the Mt. Usu 1663 eruption, in Hokkaido, Japan (to quote only two examples) to flee before the eruptions started. During the second half of the 19th century seismographs were installed on some volcanoes, and the link between seismic and eruptive activity started to be assessed on a firmer scientific basis. The first systematic observations of the correlations existing between seismic activity and volcanic eruptions were probably those carried out at Mt. Vesuvius by Luigi Palmieri in 1856. Palmieri was the Director of Osservatorio Vesuviano and built an electromagnetic seismograph with the aim of "making visible the smallest ground motions by recording them on paper and indicating direction, intensity and duration". He was able to show the relationship between earthquakes and the different phases of volcanic activity. He identified the harmonic tremor which he indicated was a precursor of volcanic activity: "the characteristic feature of the ground mo tions preceding eruption is its continuity . . . (before the eruption of 1861) the electromagnetic seismograph began to show a continuous tremor". The Palmieri seismograph was also utilized in Japan until 1883, when it was replaced by the new Gray-Milne seismographs, and, later, by the Omori in struments.

Written in flowing prose & supplemented with compelling photography, this is the story of a new active volcano in the middle of a Mexican cornfield & its effect on a local agrarian people.