Shallow and deep controls on lava lake surface motion at Kīlauea Volcano

Journal of Volcanology and Geothermal Research
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Abstract

Lava lakes provide a rare window into magmatic behavior, and lake surface motion has been used to infer deeper properties of the magmatic system. At Halema'uma'u Crater, at the summit of Kīlauea Volcano, multidisciplinary observations for the past several years indicate that lava lake surface motion can be broadly divided into two regimes: 1) stable and 2) unstable. Stable behavior is driven by lava upwelling from deeper in the lake (presumably directly from the conduit) and is an intrinsic process that drives lava lake surface motion most of the time. This stable behavior can be interrupted by periods of unstable flow (often reversals) driven by spattering – a shallowly-rooted process often extrinsically triggered by small rockfalls from the crater wall. The bursting bubbles at spatter sources create void spaces and a localized surface depression which draws and consumes surrounding surface crust. Spattering is therefore a location of lava downwelling, not upwelling. Stable (i.e. deep, upwelling-driven) and unstable (i.e. shallow, spattering-driven) behavior often alternate through time, have characteristic surface velocities, flow directions and surface temperature regimes, and also correspond to changes in spattering intensity, outgassing rates, lava level and seismic tremor. These results highlight that several processes, originating at different depths, can control the motion of the lava lake surface, and long-term interdisciplinary monitoring is required to separate these influences. These observations indicate that lake surface motion is not always a reliable proxy for deeper lake or magmatic processes. From these observations, we suggest that shallow outgassing (spattering), not lake convection, drives the variations in lake motion reported at Erta 'Ale lava lake.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Shallow and deep controls on lava lake surface motion at Kīlauea Volcano
Series title Journal of Volcanology and Geothermal Research
DOI 10.1016/j.jvolgeores.2016.11.010
Volume 328
Year Published 2016
Language English
Publisher Elsevier
Contributing office(s) Volcano Science Center
Description 14 p.
First page 247
Last page 261
Country United States
State Hawaii
Other Geospatial Halema`uma`u Crater, Kīlauea Volcano