Lava flow morphology at an erupting andesitic stratovolcano: A satellite perspective on El Reventador, Ecuador

Journal of Volcanology and Geothermal Research
By: , and 

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Abstract

Lava flows pose a significant hazard to infrastructure and property located close to volcanoes, and understanding how flows advance is necessary to manage volcanic hazard during eruptions. Compared to low-silica basaltic flows, flows of andesitic composition are infrequently erupted and so relatively few studies of their characteristics and behaviour exist. We use El Reventador, Ecuador as a target to investigate andesitic lava flow properties during a 4.5 year period of extrusive eruption between February 2012 and August 2016. We use satellite radar to map the dimensions of 43 lava flows and look at variations in their emplacement behaviour over time. We find that flows descended the north and south flanks of El Reventador, and were mostly emplaced over durations shorter than the satellite repeat interval of 24 days. Flows ranged in length from 0.3 to 1.7 km, and the length of flows generally decreased over the observation period. We measure a decrease in flow volume with time that is correlated with a long-term exponential decrease in effusion rate, and propose that this behaviour is caused by temporary magma storage in the conduit acting as magma capacitor between the magma reservoir and the surface. We use the dimensions of flow levées and widths to estimate the flow yield strengths. We observe that some flows were diverted by topographic obstacles, and compare measurements of decreased channel width and increased flow thickness at the obstacles with observations from laboratory experiments. Radar observations, such as those presented here, could be used to map and measure properties of evolving lava flow fields at other remote or difficult to monitor volcanoes.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Lava flow morphology at an erupting andesitic stratovolcano: A satellite perspective on El Reventador, Ecuador
Series title Journal of Volcanology and Geothermal Research
DOI 10.1016/j.jvolgeores.2019.01.009
Volume 372
Year Published 2019
Language English
Publisher Elsevier
Contributing office(s) Volcano Science Center
Description 14 p.
First page 34
Last page 47
Country Ecuador
Other Geospatial El Reventador