In situ observation of nanolite growth in volcanic melt: A driving force for explosive eruptions

DOI: 10.1126/sciadv.abb0413

Authors: Danilo Di Genova (Clausthal University of Technology; University of Bristol; Universität Bayreuth) , Richard A. Brooker (University of Bristol) , Heidy M. Mader (University of Bristol) , James W. E. Drewitt (University of Bristol) , Alessandro Longo (ESRF - The European Synchrotron; ISMN-CNR) , Joachim Deubener (Clausthal University of Technology) , Daniel R. Neuville (IPGP-CNRS) , Sara Fanara (University of Göttingen) , Olga Shebanova (Diamond Light Source) , Simon Anzellini (Diamond Light Source) , Fabio Arzilli (University of Manchester) , Emily C. Bamber (University of Manchester) , Louis Hennet (CNRS-CEMHTI) , Giuseppe La Spina (University of Manchester) , Nobuyoshi Miyajima (Universität Bayreuth)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Science Advances , VOL 6

State: Published (Approved)
Published: September 2020
Diamond Proposal Number(s): 17615 , 20447

Abstract: Although gas exsolution is a major driving force behind explosive volcanic eruptions, viscosity is critical in controlling the escape of bubbles and switching between explosive and effusive behavior. Temperature and composition control melt viscosity, but crystallization above a critical volume (>30 volume %) can lock up the magma, triggering an explosion. Here, we present an alternative to this well-established paradigm by showing how an unexpectedly small volume of nano-sized crystals can cause a disproportionate increase in magma viscosity. Our in situ observations on a basaltic melt, rheological measurements in an analog system, and modeling demonstrate how just a few volume % of nanolites results in a marked increase in viscosity above the critical value needed for explosive fragmentation, even for a low-viscosity melt. Images of nanolites from low-viscosity explosive eruptions and an experimentally produced basaltic pumice show syn-eruptive growth, possibly nucleating a high bubble number density.

Diamond Keywords: Volcanology

Subject Areas: Earth Science


Instruments: I15-Extreme Conditions , I22-Small angle scattering & Diffraction

Added On: 24/09/2020 14:29

Documents:
eabb0413.full.pdf

Discipline Tags:

Earth Sciences & Environment Natural disaster Geology Geochemistry

Technical Tags:

Diffraction Scattering Small Angle X-ray Scattering (SAXS) Wide Angle X-ray Scattering (WAXS)