Volcanic edifice weakening via devolatilization reactions
Version of Record online: 1 JUL 2011
© 2011 The Authors Geophysical Journal International © 2011 RAS
Geophysical Journal International
Volume 186, Issue 3, pages 1073–1077, September 2011
How to Cite
Mollo, S., Vinciguerra, S., Iezzi, G., Iarocci, A., Scarlato, P., Heap, M. J. and Dingwell, D. B. (2011), Volcanic edifice weakening via devolatilization reactions. Geophysical Journal International, 186: 1073–1077. doi: 10.1111/j.1365-246X.2011.05097.x
- Issue online: 17 AUG 2011
- Version of Record online: 1 JUL 2011
- Accepted 2011 June 2. Received 2011 May 19; in original form 2011 March 18
- Phase transitions;
- Experimental volcanism;
- Volcanic hazards and risks
Edifice instability, that can result in catastrophic flank collapse, is a fundamental volcanic hazard. The subvolcanic basement can encourage such instability, especially if it is susceptible to mechanical weakening by devolatilization reactions near magmatic temperatures. For this reason, understanding how the physical and chemical properties of representative lithologies deteriorate at high temperatures is potentially highly relevant for volcanic hazard mitigation. This is particularly true for sedimentary rock, commonly found underlying volcanic edifices worldwide, that undergo rapid deterioration even under modest temperatures.
Therefore, here we present the first experimental study of devolatilization reactions, induced by magmatic temperatures, on sedimentary rock comprising a subvolcanic basement. Our results show that, for a marly limestone representative of the basement at Mt Etna, devolatilization reactions, namely the dehydroxylation of clay minerals and the decarbonation of calcium carbonate, result in a dramatic reduction of mechanical strength and seismic velocities. These temperature-driven reactions can promote volcanic instability at stresses much lower than previously estimated.