[Research Article] Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflow

Large volcanic eruptions on Earth commonly occur with a collapse of the roof of a crustal magma reservoir, forming a caldera. Only a few such collapses occur per century, and the lack of detailed observations has obscured insight into the mechanical interplay between collapse and eruption. We use multiparameter geophysical and geochemical data to show that the 110-square-kilometer and 65-meter-deep collapse of Bárdarbunga caldera in 2014–2015 was initiated through withdrawal of magma, and lateral migration through a 48-kilometers-long dike, from a 12-kilometers deep reservoir. Interaction between the pressure exerted by the subsiding reservoir roof and the physical properties of the subsurface flow path explain the gradual, near-exponential decline of both collapse rate and the intensity of the 180-day-long eruption.
Authors: Magnús T. Gudmundsson, Kristín Jónsdóttir, Andrew Hooper, Eoghan P. Holohan, Sæmundur A. Halldórsson, Benedikt G. Ófeigsson, Simone Cesca, Kristín S. Vogfjörd, Freysteinn Sigmundsson, Thórdís Högnadóttir, Páll Einarsson, Olgeir Sigmarsson, Alexander H. Jarosch, Kristján Jónasson, Eyjólfur Magnússon, Sigrún Hreinsdóttir, Marco Bagnardi, Michelle M. Parks, Vala Hjörleifsdóttir, Finnur Pálsson, Thomas R. Walter, Martin P. J. Schöpfer, Sebastian Heimann, Hannah I. Reynolds, Stéphanie Dumont, Eniko Bali, Gudmundur H. Gudfinnsson, Torsten Dahm, Matthew J. Roberts, Martin Hensch, Joaquín M. C. Belart, Karsten Spaans, Sigurdur Jakobs...

Source: ScienceNOW - July 14, 2016 Category: Science Authors: Magnús T. Gudmundsson Source Type: news