Diverting lava flows in the lab

Nature Geoscience
By: , and 

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Abstract

Recent volcanic eruptions in Hawai'i, Iceland and Cape Verde highlight the challenges of mitigating hazards when lava flows threaten infrastructure. Diversion barriers are the most common form of intervention, but historical attempts to divert lava flows have met with mixed success and there has been little systematic analysis of optimal barrier design. We examine the interaction of viscous flows of syrup and molten basalt with barriers in the laboratory. We find that flows thicken immediately upslope of an obstacle, forming a localized bow wave that can overtop barriers. Larger bow waves are generated by faster flows and by obstacles oriented at a high angle to the flow direction. The geometry of barriers also influences flow behaviour. Barriers designed to split or dam flows will slow flow advance, but cause the flow to widen, whereas oblique barriers can effectively divert flows, but may also accelerate flow advance. We argue that to be successful, mitigation of lava-flow hazards must incorporate the dynamics of lava flow–obstacle interactions into barrier design. The same generalizations apply to the effect of natural topographic features on flow geometry and advance rates.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Diverting lava flows in the lab
Series title Nature Geoscience
DOI 10.1038/ngeo2470
Volume 8
Year Published 2015
Language English
Publisher Nature Publishing Group
Contributing office(s) Volcano Science Center
Description 3 p.
First page 494
Last page 496