| 1. |
- Carn, Simon, et al.
(författare)
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Daily monitoring of Ecuadorian volcanic degassing from space
- 2008
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Ingår i: Journal of Volcanology and Geothermal Research. - 0377-0273. ; 176:1, s. 141-150
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Tidskriftsartikel (refereegranskat)abstract
- We present daily measurements of sulfur dioxide (SO2) emissions from active volcanoes in Ecuador and southern Colombia between September 2004 and September 2006, derived from the Ozone Monitoring Instrument (OMI) on NASA's EOS/Aura satellite. OMI is an ultraviolet/visible spectrometer with an unprecedented combination of spatial and spectral resolution, and global coverage, that permits daily measurements of passive volcanic degassing from space. We use non-interactive processing methods to automatically extract daily SO2 burdens and information on SO2 sources from the OMI datastream. Maps of monthly average SO2 vertical columns retrieved by OMI over Ecuador and S. Colombia are also used to illustrate variations in regional SO2 loading and to pinpoint sources. The dense concentration of active volcanoes in Ecuador provides a stringent test of OMI's ability to distinguish SO2 from multiple emitting sources. Our analysis reveals that Tungurahua, Reventador and Galeras were responsible for the bulk of the SO2 emissions in the region in the timeframe of our study, with no significant SO2 discharge detected from Sangay. At Galeras and Reventador, we conclude that OMI can detect variations in SO2 release related to cycles of conduit sealing and degassing, which are a critical factor in hazard assessment. The OMI SO2 data for Reventador are the most extensive sequence of degassing measurements available for this remote volcano, which dominated regional SO2 production in June–August 2005. At Tungurahua, the OMI measurements span the waning stage of one eruptive cycle and the beginning of another, and we observe increasing SO2 burdens in the months prior to explosive eruptions of the volcano in July and August 2006. Cumulative SO2 loadings measured by OMI yield a total of ~ 1.16 Tg SO2 emitted by volcanoes on mainland Ecuador/S. Colombia between September 2004 and September 2006; as much as 95% of this SO2 may originate from non-eruptive degassing. Approximate apportionment of the total SO2 loading indicates that ~ 40% originated from Tungurahua, with ~ 30% supplied by both Reventador and Galeras. These measurements of volcanic SO2 degassing in Ecuador confirm OMI's potential as an effective, economical and risk-free tool for daily monitoring of SO2 emissions from hazardous volcanoes.
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| 2. |
- Fischer, Tobias P., et al.
(författare)
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The emissions of CO2 and other volatiles from the world's subaerial volcanoes
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Volcanoes are the main pathway to the surface for volatiles that are stored within the Earth. Carbon dioxide (CO2) is of particular interest because of its potential for climate forcing. Understanding the balance of CO2 that is transferred from the Earth's surface to the Earth's interior, hinges on accurate quantification of the long-term emissions of volcanic CO2 to the atmosphere. Here we present an updated evaluation of the world's volcanic CO2 emissions that takes advantage of recent improvements in satellite-based monitoring of sulfur dioxide, the establishment of ground-based networks for semi-continuous CO2-SO2 gas sensing and a new approach to estimate key volcanic gas parameters based on magma compositions. Our results reveal a global volcanic CO2 flux of 51.3 +/- 5.7 Tg CO2/y (11.7 x 10(11) mol CO2/y) for non-eruptive degassing and 1.8 +/- 0.9 Tg/y for eruptive degassing during the period from 2005 to 2015. While lower than recent estimates, this global volcanic flux implies that a significant proportion of the surface-derived CO2 subducted into the Earth's mantle is either stored below the arc crust, is efficiently consumed by microbial activity before entering the deeper parts of the subduction system, or becomes recycled into the deep mantle to potentially form diamonds.
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| 3. |
- Liu, E. J., et al.
(författare)
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Aerial strategies advance volcanic gas measurements at inaccessible, strongly degassing volcanoes
- 2020
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Ingår i: Science advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:44
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Tidskriftsartikel (refereegranskat)abstract
- Volcanic emissions are a critical pathway in Earth's carbon cycle. Here, we show that aerial measurements of volcanic gases using unoccupied aerial systems (UAS) transform our ability to measure and monitor plumes remotely and to constrain global volatile fluxes from volcanoes. Combining multi-scale measurements from ground-based remote sensing, long-range aerial sampling, and satellites, we present comprehensive gas fluxes-3760 ± [600, 310] tons day-1 CO2 and 5150 ± [730, 340] tons day-1 SO2-for a strong yet previously uncharacterized volcanic emitter: Manam, Papua New Guinea. The CO2/ST ratio of 1.07 ± 0.06 suggests a modest slab sediment contribution to the sub-arc mantle. We find that aerial strategies reduce uncertainties associated with ground-based remote sensing of SO2 flux and enable near-real-time measurements of plume chemistry and carbon isotope composition. Our data emphasize the need to account for time averaging of temporal variability in volcanic gas emissions in global flux estimates.
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| 4. |
- Smets, Benoît, et al.
(författare)
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Detailed multidisciplinary monitoring reveals pre- and co-eruptive signals at Nyamulagira volcano (North Kivu, Democratic Republic of Congo)
- 2014
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Ingår i: Bulletin of Volcanology. - : Springer Science and Business Media LLC. - 0258-8900 .- 1432-0819. ; 76:787, s. 1-35
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a thorough description of Nyamulagira’s January 2010 volcanic eruption (North Kivu, Democratic Republic of Congo), based on a combination of field observation and ground-based and space-borne data. It is the first eruption in the Virunga Volcanic Province that has been described by a combination of several modern monitoring techniques. The 2010 eruption lasted 26 days and emitted ∼45.5 × 106 m3 of lava. Field observations divided the event into four eruptive stages delimited by major changes in effusive activity. These stages are consistent with those described by Pouclet (1976) for historical eruptions of Nyamulagira. Co-eruptive signals from ground deformation, seismicity, SO2 emission and thermal flux correlate with the eruptive stages. Unambiguous pre-eruptive ground deformation was observed 3 weeks before the lava outburst, coinciding with a small but clear increase in the short period seismicity and SO2 emission. The 3 weeks of precursors contrasts with the only precursory signal previously recognized in the Virunga Volcanic Province, the short-term increase of tremor and long period seismicity, which, for example, were only detected less than 2 h prior to the 2010 eruption. The present paper is the most detailed picture of a typical flank eruption of this volcano. It provides valuable tools for re-examining former—mostly qualitative—descriptions of historical Nyamulagira eruptions that occurred during the colonial period.
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| 5. |
- Verdurme, Pauline, et al.
(författare)
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Lava Volume from Remote Sensing Data: Comparisons with Reverse Petrological Approaches for Two Types of Effusive Eruption
- 2022
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Ingår i: Remote Sensing. - : MDPI AG. - 2072-4292. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- Five effusive eruptions of Piton de la Fournaise (La Réunion) are analyzed to investigate temporal trends of erupted mass and sulfur dioxide (SO2) emissions. Daily SO2 emissions are acquired from three ultraviolet (UV) satellite instruments (the Ozone Monitoring Instrument (OMI), the Ozone Mapping and Profiler Suite (OMPS), and the Tropospheric Monitoring Instrument (TROPOMI)) and an array of ground-based UV spectrometers (Network for Observation of Volcanic and Atmospheric Change (NOVAC)). Time-averaged lava discharge rates (TADRs) are obtained from two automatic satellite-based hot spot detection systems: MIROVA and MODVOLC. Assuming that the lava volumes measured in the field are accurate, the MIROVA system gave the best estimation of erupted volume among the methods investigated. We use a reverse petrological method to constrain pre-eruptive magmatic sulfur contents based on observed SO2 emissions and lava volumes. We also show that a direct petrological approach using SO2 data might be a viable alternative for TADR estimation during cloudy weather that compromises hot spot detection. In several eruptions we observed a terminal increase in TADR and SO2 emissions after initial emission of evolved degassed magma. We ascribe this to input of deeper, volatile-rich magma into the plumbing system towards the end of these eruptions. Furthermore, we find no evidence of volatile excess in the five eruptions studied, which were thus mostly fed by shallow degassed magma.
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