Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Volcano infrasonic signals and magma degassing
T2 - first-order experimental insights and application to Stromboli
AU - Lane, Stephen J.
AU - James, Michael
AU - Corder, Steven B.
PY - 2013/9
Y1 - 2013/9
N2 - We demonstrate the rise and expansion of a gas slug as a fluid dynamic source mechanism for infrasonic signals generated by gas puffing and impulsive explosions at Stromboli. The fluid dynamics behind the rise, expansion and burst of gas slugs in the confines of an experimental tube can be characterised into different regimes. Passive expansion occurs for small gas masses, where negligible dynamic gas over-pressure develops during bubble ascent and, prior to burst, meniscus oscillation forms an important infrasonic source. With increasing gas mass, a transition regime emerges where dynamic gas over-pressure is significant. For larger gas masses, this regime transforms to fully explosive behaviour, where gas over-pressure dominates as an infrasonic source and bubble bursting is not a critical factor. The rate of change of excess pressure in the experimental tube was used to generate synthetic infrasonic waveforms. Qualitatively, the waveforms compare well to infrasonic waveforms measured from a range of eruptions at Stromboli. Assuming pressure continuity during flow through the vent, and applying dimensionless arguments from the first-order experiments, allows estimation of eruption metrics from infrasonic signals measured at Stromboli. Values of bubble length, gas mass and over-pressure calculated from infrasonic signals are in excellent agreement with those derived by independent means for eruptions at Stromboli, therefore providing a method of estimating eruption metrics from infrasonic measurement.
AB - We demonstrate the rise and expansion of a gas slug as a fluid dynamic source mechanism for infrasonic signals generated by gas puffing and impulsive explosions at Stromboli. The fluid dynamics behind the rise, expansion and burst of gas slugs in the confines of an experimental tube can be characterised into different regimes. Passive expansion occurs for small gas masses, where negligible dynamic gas over-pressure develops during bubble ascent and, prior to burst, meniscus oscillation forms an important infrasonic source. With increasing gas mass, a transition regime emerges where dynamic gas over-pressure is significant. For larger gas masses, this regime transforms to fully explosive behaviour, where gas over-pressure dominates as an infrasonic source and bubble bursting is not a critical factor. The rate of change of excess pressure in the experimental tube was used to generate synthetic infrasonic waveforms. Qualitatively, the waveforms compare well to infrasonic waveforms measured from a range of eruptions at Stromboli. Assuming pressure continuity during flow through the vent, and applying dimensionless arguments from the first-order experiments, allows estimation of eruption metrics from infrasonic signals measured at Stromboli. Values of bubble length, gas mass and over-pressure calculated from infrasonic signals are in excellent agreement with those derived by independent means for eruptions at Stromboli, therefore providing a method of estimating eruption metrics from infrasonic measurement.
KW - volcano infrasonics
KW - magma degassing
KW - eruption quantification
KW - slug flow
KW - Taylor bubble
KW - analogue experiments
UR - http://www.scopus.com/inward/record.url?scp=84880247878&partnerID=8YFLogxK
U2 - 10.1016/j.epsl.2013.06.048
DO - 10.1016/j.epsl.2013.06.048
M3 - Journal article
VL - 377-378
SP - 169
EP - 179
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
SN - 0012-821X
ER -