Conference proceeding
Contrasting degassing behaviors before and after a shift in eruptive style at Sinabung Volcano, Indonesia
American Geophysical Union Fall Meeting, Vol.2018
Dec 2018
Abstract
Volcanic activity is classically described as effusive or explosive in nature. However, many eruptions exhibit both behaviors alternatively, and sometimes simultaneously. This is especially true at volcanic centers of intermediate composition, where effusive activity such as the growth of a lava dome or lava flow is often accompanied by sporadic or regular explosions. Such systems offer unique opportunities for research, as their frequent changes in eruptive styles can be documented with a variety of geophysical techniques to investigate the source conditions that give rise to explosions. In this work, we present gas emission data acquired with SO (sub 2) cameras at Sinabung volcano during a transition phase between quiescent degassing and explosive activity. Sinabung is an andesitic stratovolcano located on the island of Sumatra in Indonesia. Its most recent eruption period has seen the effusion of a 3 km long andesite lava flow and has been punctuated by occasional explosions (VEI 1-3), sending ash columns up to 10 km high (Global Volcanism Program, 2013-2018). On 15th June 2018, the activity at Sinabung shifted from a phase of quiescent degassing to series of small to moderate ash bursts, with the resulting plumes reaching heights of a few hundreds of meters to a kilometer above the crater, often bent by winds. We acquired data on two separate days immediately prior to the explosive activity (June 13-14), and on one day after the onset of the explosive activity (June 20). Degassing patterns on June 14 were distinct from those documented on June 13, with a general increase in the overall emission rate, and the appearance of periodic gas burst with periods on the order of 4-5 mins. This change in degassing behavior even before the onset of the explosions indicates a change in source dynamics, potentially the cause for the impending change in activity. On June 20, emissions remained high, but degassing patterns were much more vigorous, and no distinct bursts were discernable. SO (sub 2) cameras provide the means to monitor degassing at very high frequency (< 1 Hz). They allow the identification of changes in system behavior at Sinabung, not only in terms of increases or decreases in the emission rate, but more importantly in the period and intensity of gas bursts, making them a well-suited tool to investigate source dynamics.
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Details
- Title
- Contrasting degassing behaviors before and after a shift in eruptive style at Sinabung Volcano, Indonesia
- Creators
- J. F. Smekens - Northern Arizona UniversityChristine R. SealingE. CareyL. VanderkluysenB. B. CarrG. I. MarliyaniA. HarijokoC. S. EdwardsAnonymous
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2018
- Conference
- American Geophysical Union Fall Meeting (2018)
- Publisher
- American Geophysical Union
- Resource Type
- Conference proceeding
- Language
- English
- Academic Unit
- Biodiversity, Earth, and Environmental Science (BEES)
- Identifiers
- 991021015346604721