Cookies

We use cookies to ensure that we give you the best experience on our website. You can change your cookie settings at any time. Otherwise, we'll assume you're OK to continue.

Durham University

Department of Earth Sciences

Profile

Publication details for Dr Fabian Wadsworth

Wadsworth, Fabian B., Vasseur, Jérémie, von Aulock, Felix W., Hess, Kai-Uwe, Scheu, Bettina, Lavallée, Yan & Dingwell, Donald B. (2014). Nonisothermal viscous sintering of volcanic ash. Journal of Geophysical Research: Solid Earth 119(12): 8792-8804.

Author(s) from Durham

Abstract

Volcanic ash is often deposited in a hot state. Volcanic ash containing glass, deposited above the glass transition interval, has the potential to sinter viscously both to itself (particle‐particle) and to exposed surfaces. Here we constrain the kinetics of this process experimentally under nonisothermal conditions using standard glasses. In the absence of external load, this process is dominantly driven by surface relaxation. In such cases the sintering process is rate limited by the melt viscosity, the size of the particles and the melt‐vapor interfacial tension. We propose a polydisperse continuum model that describes the transition from a packing of particles to a dense pore‐free melt and evaluate its efficacy in describing the kinetics of volcanic viscous sintering. We apply our model to viscous sintering scenarios for cooling crystal‐poor rhyolitic ash using the 2008 eruption of Chaitén volcano as a case example. We predict that moderate linear cooling rates of > 0.1°C min−1 can result in the common observation of incomplete sintering and the preservation of pore networks.