Publication Date

April 2017

Advisor(s)

Johan Varekamp

Major

Earth & Environmental Sciences

Language

English (United States)

Abstract

Expansive sinuous lava channels are visible from remote imagery on the planets and on Earth, but observations of active massive lava flows are far and few between. To understand the origin of extraterrestrial lava channels, we use the emplacement mechanisms of medium to large flows on Earth. This study aims at reconstructing the flow history of a branch of the Lakagígar lava, with an emphasis on the influence of ponding on flow morphology. This study on the 1783 Laki, Iceland eruption used 1851 thickness measurements of slabby pahoehoe plates, distributed over several km within the Lake fissure #3 channel structure to estimate its duration and extent. The slab thickness data were translated into cooling times and used as a terrestrial chronometer to estimate the extent and duration of ponding within this Laki channel. Ponding was interrupted by surges and lava escape, which lead to separation of crusts, detachment, and fissure formation. We used high resolution UAV imagery taken on site to study the spatial distribution of the measured slab values. Data and calculations show a minimum of a 12.5 hour long ponding event, with at least two other minor, channel-wide surge events occurring at ~ 2.5 and ~5.5 hours after the inflated flow emplacement. The study also explores formation processes of slab pahoehoe and the use of slab thickness as a volcano chronometer, applicable towards investigating locally confined flow kinematics.

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