Volcanic lateral collapse processes in mafic arc edifices: a review of their driving processes, types and consequences

Research output: Contribution to journalReview articlepeer-review

Authors

  • Jorge E. Romero
  • Margherita Polacci
  • Shigeru Kitamura
  • Daniel Tormey
  • Gerd Sielfeld
  • Fabio Arzilli
  • Giuseppe La Spina
  • Luis Franco
  • Mike Burton
  • Edmundo Polanco

Colleges, School and Institutes

External organisations

  • University of Manchester
  • Niigata University
  • Catalyst Environmental Solutions
  • Pontificia Universidad Católica de Chile
  • Servicio Nacional de Geología y Minería

Abstract

Volcanic cones are frequently near their gravitational stability limit, which can lead to lateral collapse of the edifice, causing extensive environmental impact, property damage, and loss of life. Here, we examine lateral collapses in mafic arc volcanoes, which are relatively structurally simple edifices dominated by a narrow compositional range from basalts to basaltic andesites. This still encompasses a broad range of volcano dimensions, but the magma types erupted in these systems represent the most abundant type of volcanism on Earth and rocky planets. Their often high magma output rates can result in rapid construction of gravitationally unstable edifices susceptible both to small landslides but also to much larger-scale catastrophic lateral collapses. Although recent studies of basaltic shield volcanoes provide insights on the largest subaerial lateral collapses on Earth, the occurrence of lateral collapses in mafic arc volcanoes lacks a systematic description, and the features that make such structures susceptible to failure has not been treated in depth. In this review, we address whether distinct characteristics lead to the failure of mafic arc volcanoes, or whether their propensity to collapse is no different to failures in volcanoes dominated by intermediate (i.e., andesitic-dacitic) or silicic (i.e., rhyolitic) compositions? We provide a general overview on the stability of mafic arc edifices, their potential for lateral collapse, and the overall impact of large-scale sector collapse processes on the development of mafic magmatic systems, eruptive style and the surrounding landscape. Both historical accounts and geological evidence provide convincing proofs of recurrent (and even repetitive) largescale (>0.5 km3) lateral failure of mafic arc volcanoes. The main factors contributing to edifice instability in these volcanoes are: (1) frequent sheet-like intrusions accompanied by intense deformation and seismicity; (2) shallow hydrothermal systems weakening basaltic rocks and reducing their overall strength; (3) large edifices with slopes near the critical angle; (4) distribution along fault systems, especially in transtensional settings, and; (5) susceptibility to other external forces such as climate change. These factors are not exclusive of mafic volcanoes, but probably enhanced by the rapid building of such edifices.

Bibliographic note

Funding Information: JR is supported through a Dean’s Doctoral Scholar Awards of the University of Manchester and NSFGEO-NERC-funded project DisEqm (NERC Reference: NE/N018575/1) and V-PLUS projects. Publisher Copyright: © 2021 Romero, Polacci, Watt, Kitamura, Tormey, Sielfeld, Arzilli, La Spina, Franco, Burton and Polanco.

Details

Original languageEnglish
Article number639825
JournalFrontiers in Earth Science
Volume9
Publication statusPublished - 12 May 2021

Keywords

  • Basaltic volcanism, Debris avalanche, Decompression, Edifice instability, Landslide, Lateral collapse, Unloading, Volcanic geomorphology

ASJC Scopus subject areas

Sustainable Development Goals