X-raying an unusual patient : imaging analogue experiments of volcanic intrusions using X-ray Computed Tomography

Sam Poppe, PhD student at the Vrije Universiteit Brussel, will present his work on "X-raying an unusual patient : imaging analogue experiments of volcanic intrusions using X-ray Computed Tomography".

Sam Poppe acquiring photos for a photogrammetric reconstruction of the Chahalé summit crater of Karthala volcano, Grande Comore Island, during field work in september 2015.


Magma plumbing systems below volcanic edifices are complex. They consist of diverse elements through which the magma is transported to its final position in the shallow crust as a magmatic intrusion, or further on to the surface to feed volcanic eruptions. Field examples from the Comoros archipelago demonstrate it is possible to observe the complex geometries and structural deformation induced by magmatic intrusions in the shallowest part of eroded volcanic systems. Nevertheless, we rely on volcano monitoring techniques to constrain the ground surface deformation during actual events of magma intrusion at active volcanic systems, and are physically incapable of directly observing the mechanics and dynamics of an ongoing injection of magma below the earth’s surface.

During recent years however, X-ray computed tomography scanning (XCT) has made important technological advances, now making it possible to scan objects in less than one second at resolutions of few tens to hundreds of micrometers. As a first step in applying XCT methods to analogue experiments in the geosciences, we present a characterization of the geomechanical behavior and X-ray absorption characteristics of brittle material mixtures typically used. We show amongst others, that the mechanical characteristics of commonly used sand-and-plaster mixtures contain a stick-slip component, in contrast to the purely brittle Mohr-coulomb behavior commonly desired by the dimensional scaling laws that govern the force balance in analogue geo-models.

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Sam Poppe is a PhD-student at the Vrije Univerisiteit Brussel, Belgium and Aspirant of the FWO-Flanders. His research in volcanology mainly focuses on analogue modeling of various processes of volcano deformation compared to field observations; and the assessment of volcanic hazards at active volcanoes in densely populated areas in developing countries, mainly in Africa.

Published Oct. 19, 2015 9:16 AM - Last modified Oct. 19, 2015 11:57 AM