Análisis de las columnas eruptivas del Volcán Chichón marzo-abril, 1982. Velocidad de salida, presión de la cámara magmatica y energía cinética asociada

Abstract

Based on the volumes of the erupted material and duratlon times of the March-April 1982 eruptions of the El Chichón volcano, the heights and flow velocities of the eruptive columns are evaluated. The velocities obtained are higher than 400 m/sec in the March 28 eruption and of the order of 1 000 m/sec in the April 4 eruption. With the velocity data the Interna! pressure in the fragmentation level of the magma chamber are computed. Assuming that the generated pressure is a function of the water content and gasification temperature, the ·percentage of water is evaluated for the different eruptions. The high percentage ofwater (15%) in the April 3 eruption, as well as the sudden growth of the crater, were probably the source of the observed surges. The kinetic and termal energy, as well as the efficiency of the thermal to kinetic energy conversion are evaluated for each eruption.