Image-based measurement of flux variation in distal regions of active lava flows.

Lancaster Environment Centre

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Rights statement: Copyright 2007 by the American Geophysical Union.
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https://doi.org/10.1029/2006GC001448
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Keywords

close-range photogrammetry, thermal imaging, lava flow, Etna, effusion rate, rheology.

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Image-based measurement of flux variation in distal regions of active lava flows. / James, Mike R.; Pinkerton, Harry; Robson, S.
In: Geochemistry, Geophysics, Geosystems, Vol. 8, No. 3, Q03006, 13.03.2007.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Bibtex

@article{ccb7211d45eb4239bc09e3bbc6411843,

title = "Image-based measurement of flux variation in distal regions of active lava flows.",

abstract = "Understanding the processes involved with the advance of lava flows is critical for improving hazard assessments at many volcanoes. Here, we describe the application of computer vision and oblique photogrammetric techniques to visible and thermal images of active 'a'ā flows in order to investigate distal flow processes at Mount Etna, Sicily. Photogrammetric surveys were carried out to produce repeated topographic data sets for calculation of volumetric lava flux at the flow-fronts. Velocity profiles from a distal channel were obtained by rectification of a thermal image sequence and are used to investigate the rheological properties of the lava. Significant variations of the magma flux were observed, and pulses of increased flux arrived within the flow-front region on timescales of several hours. The pulses are believed to be the distal result of more frequent flux changes observed in the vent region. Hence they reflect the importance of flow processes which are believed to cause the coalescence of flux pulses along the channel system as well as short-period variations in effusion rate. In considering advance processes for the individual flow-fronts, it must be assumed that they were fed by a highly unsteady flux, which was volumetrically at least an order of magnitude lower than that observed near the vent.",

keywords = "close-range photogrammetry, thermal imaging, lava flow, Etna, effusion rate, rheology.",

author = "James, {Mike R.} and Harry Pinkerton and S. Robson",

note = "Copyright (2007) American Geophysical Union.",

year = "2007",

month = mar,

day = "13",

doi = "10.1029/2006GC001448",

language = "English",

volume = "8",

journal = "Geochemistry, Geophysics, Geosystems",

issn = "1525-2027",

publisher = "John Wiley & Sons, Ltd",

number = "3",

}

RIS

TY - JOUR

T1 - Image-based measurement of flux variation in distal regions of active lava flows.

AU - James, Mike R.

AU - Pinkerton, Harry

AU - Robson, S.

PY - 2007/3/13

Y1 - 2007/3/13

N2 - Understanding the processes involved with the advance of lava flows is critical for improving hazard assessments at many volcanoes. Here, we describe the application of computer vision and oblique photogrammetric techniques to visible and thermal images of active 'a'ā flows in order to investigate distal flow processes at Mount Etna, Sicily. Photogrammetric surveys were carried out to produce repeated topographic data sets for calculation of volumetric lava flux at the flow-fronts. Velocity profiles from a distal channel were obtained by rectification of a thermal image sequence and are used to investigate the rheological properties of the lava. Significant variations of the magma flux were observed, and pulses of increased flux arrived within the flow-front region on timescales of several hours. The pulses are believed to be the distal result of more frequent flux changes observed in the vent region. Hence they reflect the importance of flow processes which are believed to cause the coalescence of flux pulses along the channel system as well as short-period variations in effusion rate. In considering advance processes for the individual flow-fronts, it must be assumed that they were fed by a highly unsteady flux, which was volumetrically at least an order of magnitude lower than that observed near the vent.

AB - Understanding the processes involved with the advance of lava flows is critical for improving hazard assessments at many volcanoes. Here, we describe the application of computer vision and oblique photogrammetric techniques to visible and thermal images of active 'a'ā flows in order to investigate distal flow processes at Mount Etna, Sicily. Photogrammetric surveys were carried out to produce repeated topographic data sets for calculation of volumetric lava flux at the flow-fronts. Velocity profiles from a distal channel were obtained by rectification of a thermal image sequence and are used to investigate the rheological properties of the lava. Significant variations of the magma flux were observed, and pulses of increased flux arrived within the flow-front region on timescales of several hours. The pulses are believed to be the distal result of more frequent flux changes observed in the vent region. Hence they reflect the importance of flow processes which are believed to cause the coalescence of flux pulses along the channel system as well as short-period variations in effusion rate. In considering advance processes for the individual flow-fronts, it must be assumed that they were fed by a highly unsteady flux, which was volumetrically at least an order of magnitude lower than that observed near the vent.

KW - close-range photogrammetry

KW - thermal imaging

KW - lava flow

KW - Etna

KW - effusion rate

KW - rheology.

U2 - 10.1029/2006GC001448

DO - 10.1029/2006GC001448

M3 - Journal article

VL - 8

JO - Geochemistry, Geophysics, Geosystems

JF - Geochemistry, Geophysics, Geosystems

SN - 1525-2027

IS - 3

M1 - Q03006

ER -

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