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| Titel |
Sulfur dioxide emissions from Alaskan volcanoes quantified using an ultraviolet SO2 camera |
| VerfasserIn |
Christoph Kern, Cynthia Werner, Peter Kelly, Ian Brewer, Dane Ketner, John Paskievitch, John Power |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250130280
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| Publikation (Nr.) |
 EGU/EGU2016-10514.pdf |
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| Zusammenfassung |
| Alaskan volcanoes are difficult targets for direct gas measurements as they are
extremely remote and their peaks are mostly covered in ice and snow throughout
the year. This makes access extremely difficult. In 2015, we were able to make
use of an ultraviolet SO2 camera to quantify the SO2 emissions from Augustine
Volcano, Redoubt Volcano, Mount Cleveland and Shishaldin Volcano in the Aleutian
Arc.
An airborne gas survey performed at Augustine Volcano in April 2015 found that
the SO2 emission rate from the summit area was below 10 tonnes per day (t/d).
SO2 camera measurements were performed two months later (June 2015) from a
snow-free area just 100 meters from the fumarole on the south side of Augustine’s
summit dome to maximize camera sensitivity. Though the visible appearance of the
plume emanating from the fumarole was opaque, the SO2 emissions were only
slightly above the 40 ppm⋅m detection limit of the SO2 camera. Still, SO2 could be
detected and compared to coincident MultiGAS measurements of SO2, CO2 and
H2S.
At Redoubt Volcano, SO2 camera measurements were conducted on 13 June 2015 from a
location 2 km to the north of the final 72x106 m3 dome extruded during the 2009 eruption.
Imagery was collected of the plume visibly emanating from the top of the dome. Preliminary
evaluation of the imagery and comparison with a coincident, helicopter-based DOAS survey
showed that SO2 emission rates had dropped below 100 t/d (down from 180 t/d measured in
April 2014).
Mount Cleveland and Shishaldin Volcano were visited in August 2015 as part of an
NSF-funded ship-based research expedition in the Central Aleutian Arc. At Mount
Cleveland, inclement weather prohibited the collection of a lengthy time-series of SO2
camera imagery, but the limited data that was collected shows an emission rate of several
hundred t/d. At Shishaldin, several hours of continuous imagery was acquired from a
location 5 km east of the summit vent. The time series shows an SO2 emission
rate of several hundred t/d as well as short-term (<5 min.) variations that could
provide insights into shallow degassing mechanisms at this highly active volcanic
center.
Our presentation will include a brief description of our SO2 camera, a system we
designed and built for rapid deployment at active volcanoes, and the results of the
measurements will be discussed. These results will be compared to other available
monitoring data and interpreted with regard to their importance for assessing the current level
of activity of these remote Alaskan volcanoes. |
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