The 1982 eruptions of El Chichón Volcano, Mexico: Stratigraphy of pyroclastic deposits

Document Type

Article

Date of Original Version

1-1-1984

Abstract

Following a repose period of 500 to 600 years, El Chichón volcano in SE Mexico erupted explosively during the months of March and April, 1982. Three major eruptions involving trachyandesite magma injected ash into the stratosphere on 29 March at 0515 GMT and on 4 April at 0139 and 1110 GMT. The first major eruption generated only tephra-fall which was dispersed ENE in the troposphere over the Yucatan Peninsula and WSW in the stratosphere towards the Pacific Ocean. The second eruption produced tephra-fall and pyroelastic surges and pyroclastic flows by repeated collapse of a lithicrich eruption column. The surge and flow activity devastated a roughly circular area (153 km2) around El Chichón to a distance of about 6 km from the vent. Nine villages within the zone were either partially or completely destroyed and loss of human life was perhaps as high as 2000. Pyroclastic flows and surges were also generated during the third eruption although ash-fall was the primary activity. As a result of both the second and third eruptions tephra was transported ENE in the troposphere and WSW in the stratosphere. The total volume of material ejected during the three major eruptions (0.50 km3 D.R.E.) is represented by tephra-fall (0.37 km3) pyroclastic surges (0.09 km3) and pyroclastic flows and debris flows (0.04 km3). As a result of the eruptions a new 1-km-wide and 300-m-deep crater was formed by the disruption and excavation of a pre-existing summit dome. © 1984.

Publication Title, e.g., Journal

Journal of Volcanology and Geothermal Research

Volume

23

Issue

1-2

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