ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2021-01-27
    Description: We report the first combined measurements of the composition and flux of gas emitted from Nyiragongo volcano by ground-based remote-sensing techniques. Ultraviolet spectroscopic measurements made in May/June 2005 and January 2006 indicate average SO2 emission rates of 38 kg s−1 and 23 kg s−1, respectively. Open-path Fourier transform infrared spectroscopic measurements obtained in May/June 2005, January 2006, and June 2007 indicate average molar proportions of 70, 24, 4.6, 0.87, 0.26, 0.11, and 0.0016% for H2O, CO2, SO2, CO, HCl, HF, and OCS, respectively. The composition of the plume was remarkably similar in 2005, 2006, and 2007, with little temporal variation in proportions of CO2, SO2, and CO, in particular, on the scale of seconds or days or even between the three field campaigns that span a period of 24 months. This stability persisted despite a wide range of degassing behaviors on the surface of the summit crater's lava lake (including discrete strombolian bursts and lava fountains) and variations in the SO2 emission rate. We explain these observations by a regime of steady state degassing in which bubbles nucleate and ascend in chemical equilibrium with the convecting magma. Short-term (seconds to minutes) temporal fluctuations in the SO2–HCl–HF composition were observed, and these are attributed to shallow degassing processes.
    Description: Published
    Description: Q02017
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Nyiragongo ; volcanic gas emissions ; FTIR ; DOAS ; remote sensing ; spectroscopy ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2021-01-27
    Description: In January 2002, Nyiragongo volcano erupted 14–34 × 106 m3 of lava from fractures on its southern flanks. The nearby city of Goma was inundated by two lava flows, which caused substantial socioeconomic disruption and forced the mass exodus of the population, leaving nearly 120,000 people homeless. Field observations showed marked differences between the lava erupted from the northern portion of the fracture system and that later erupted from the southern part. These observations are confirmed by new 238U and 232Th series radioactive disequilibria data, which show the presence of three different phases during the eruption. The lavas first erupted (T1) were probably supplied by a residual magma batch from the lava lake activity during 1994–1995. These lavas were followed by a fresh batch erupted from fissure vents as well as later (May–June 2002) from the central crater (T2). Both lava batches reached the surface via the volcano's central plumbing system, even though a separate flank reservoir may also have been involved in addition to the main reservoir. The final phase (T3) is related to an independent magmatic reservoir located much closer (or even beneath) the city of Goma. Data from the January 2002 eruption, and for similar activity in January 1977, suggest that the eruptive style of the volcano is likely to change in the future, trending toward more common occurrence of flank eruptions. If so, this would pose a significant escalation of volcanic hazards facing Goma and environs, thus requiring the implementation of different volcano-monitoring strategies to better anticipate where and when future eruptions might take place.
    Description: Published
    Description: B09202
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: Nyiragongo ; forecasting ; volcanic hazard ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2021-03-30
    Description: Over long periods of time (~Ma), we may consider the oceans, atmosphere and biosphere as a single exospheric reservoir for CO2. The geological carbon cycle describes the inputs to this exosphere from mantle degassing, metamorphism of subducted carbonates and outputs from weathering of aluminosilicate rocks (Walker et al. 1981). A feedback mechanism relates the weathering rate with the amount of CO2 in the atmosphere via the greenhouse effect (e.g., Wang et al. 1976). An increase in atmospheric CO2 concentrations induces higher temperatures, leading to higher rates of weathering, which draw down atmospheric CO2 concentrations (Berner 1991). Atmospheric CO2 concentrations are therefore stabilized over long timescales by this feedback mechanism (Zeebe and Caldeira 2008). This process may have played a role (Feulner et al. 2012) in stabilizing temperatures on Earth while solar radiation steadily increased due to stellar evolution (Bahcall et al. 2001). In this context the role of CO2 degassing from the Earth is clearly fundamental to the stability of the climate, and therefore to life on Earth. Notwithstanding this importance, the flux of CO2 from the Earth is poorly constrained. The uncertainty in our knowledge of this critical input into the geological carbon cycle led Berner and Lagasa (1989) to state that it is the most vexing problem facing us in understanding that cycle.
    Description: Published
    Description: 323-354
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: JCR Journal
    Keywords: VOLCANIC CO2 ; VOLCANIC CO2 EMISSIONS IN THE GEOLOGICAL CARBON CYCLE
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2017-04-04
    Description: Ground-based thermal imaging is becoming an increasingly important tool for volcano surveillance, however the impact of volcanic plumes on quantitative measurements of surface temperature has not been previously evaluated. Here we use a radiative transfer model to simulate gas (primarily H2O and SO2) and aerosol absorptions over the path between a thermal camera and a heat source on Stromboli volcano, Italy. A FTIR spectrometer was used to quantify path amounts of gases likely to be encountered when making thermal measurements of the active craters. We find that when using a camera sensitive from 7.5 to 13 mm, underestimates of 400 K may be produced when viewing a source with an actual temperature of 1200 K. Cameras that operate between 3 and 5 mm are somewhat less susceptible to these errors.
    Description: Published
    Description: L14311
    Description: reserved
    Keywords: NONE ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 1098429 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2012-02-03
    Description: We report results from a multidisciplinary campaign conducted at Poás volcano (Costa Rica) in March 2009. Thermal imagery of the fumaroles sited on the north side of the pyroclastic cone revealed mean apparent temperatures ranging between 25 and 40°C with a maximum apparent temperature of 80°C. The crater lake surface was characterised by mean apparent temperatures varying between 30 and 35°C and a maximum recorded value of 48°C. Thermal profiles across the lake surface revealed steady temperatures and thus thorough convective mixing. The overall mean SO2 flux emitted from the crater was 76 Mg d-1, with approximately equal contributions from both the pyroclastic cone and the lake. Analysis of gas composition using active, open-path FTIR spectroscopy indicated molar ratios of H2O/SO2 = 151, CO2/SO2 = 1.56, SO2/HCl 〉 40, and SO2/HF 〉 200 for the lake emission. The plume was also sampled using filter packs. Ion chromatographic analysis revealed the presence of abundant K+ and SO42-, with small amounts of Ca2+, Cl-, and Mg2+. This provides a detailed picture of lake surface temperature characteristics and of gas flux and composition of the plume emitted from Poás. The results are consistent with the typical non-eruptive state of this volcano.
    Description: UK Natural Environment Research Council (NERC grant NE/F004222/1) and the NERC Field Spectroscopy Facility
    Description: Published
    Description: 171-190
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: N/A or not JCR
    Description: reserved
    Keywords: Thermal imagery ; SO2 flux ; FTIR ; particles ; Poas ; 03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2012-02-03
    Description: We present results from a campaign in March 2009 to assess the current state of emissions from Masaya Volcano, Nicaragua. These results constitute one of the most comprehensive inventories to date of emissions from an active volcano and update the exceptional record of emissions from Masaya. Results from open‐path Fourier transform infrared spectroscopy and filter packs demonstrate that, in terms of H2O, SO2,CO2, HCl,and HF (molar H2O/SO2 = 63, CO2/SO2 = 2.7, SO2/HCl = 1.7, SO2/HF = 8.8), the 2009 gas composition was highly comparable to that from the 1998 to 2000 period,indicating stability of the shallow magma system. This continuity extends to certain aerosol species (molar SO2/SO42−= 190, Na+ /SO4 2−= 0.68, K+/SO4 2−= 0.71, Ca 2+/SO4 2−= 1.6 × 10−2,Mg2+/SO4 2− = 3.6 × 10−3) and, to a lesser extent, the heavy halogens (i.e., molar HCl/HBr = 2.4 × 103 , HCl/HI = 5.0 × 104). In contrast to an arlier study at Masaya, we did not detect HNO3.SO2 fluxes were low (690 Mg d−1 ), suggesting that Masaya was close to the minimum of its degassing cycle. By combining compositional results with the SO2 flux, we estimate a total volatile flux of 14,000 Mg d−1. This rate is consistent with 1−4 wt% volatile loss from a convective magma flux of 17,000–4000 kg s−1. These results will allow for a better understanding of degassing processes at Masaya and other basaltic volcanoes
    Description: NERC project “Magma dynamics at persistently degassing basaltic volcanoes: A novel approach to linking volcanic gases and magmatic volatiles within a physical model” (NE/F004222/1 and NE/F005342/1).
    Description: Published
    Description: B09215
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: JCR Journal
    Description: reserved
    Keywords: Masaya Volcano ; Degassing regime ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2017-04-04
    Description: Here we report results from a multidisciplinary field campaign at Villarrica volcano, Chile, in March 2009. A range of direct sampling and remote sensing techniqueswas employed to assess gas and aerosol emissions from the volcano, and extend the time series of measurements that have been made during recent years. Airborne traverses beneath the plume with an ultraviolet spectrometer yielded an average SO2 flux of 3.7 kg s−1. This value is similar to previous measurements made at Villarrica during periods of quiescent activity. The composition of the plume was measured at the crater rim using electrochemical sensors and, for the first time, open-path Fourier transforminfrared spectroscopy, yielding a composition of 90.5 mol% H2O, 5.7% CO2, 2.6%SO2, 0.9% HCl, 0.3% HF and b0.01% H2S. Comparison with previous gas measurements made between 2000 and 2004 shows a correlation between increased SO2/HCl ratios and periods of increased activity. Base-treated filter packs were also employed during our campaign, yielding molar ratios of HBr/SO2=1.1×10−4, HI/SO2=1.4×10−5 and HNO3/SO2=1.1×10−3 in the gas phase. Our data represent the most comprehensive gas inventory at Villarrica to date, and the first evaluation of HBr and HI emissions from a South American volcano. Sun photometry of the plume showed the near-source aerosol size distributions were bimodal with maxima at b0.1 and ~1 μm. These findings are consistent with results from analyses in 2003. Electron microscope analysis of particulatematter collected on filters showed an abundance of sphericalmicron-sized particles that are rich in Si, Mg and Al. Non-spherical, S-rich particles were also observed.
    Description: Antofagasta plc via the University of Cambridge Centre for Latin American Studies, NERC Field Spectroscopy Facility, NERC projectNE/F004222/1, “Volgaspec” projectANR-06-CATT-012-01 and from the NOVAC project. Istituto Nazionale di Geofisica e Vulcanologia and Dipartimento di Protezione Civile-Regione Sicilia. Christ's College, University of Cambridge, NERC IKIMP project, (NE/G001219/1) and NERC grantNE/G01700X/1 for financial support. NERC National Centre for EarthObservation (“Dynamic Earth and geohazards”)
    Description: Published
    Description: 62-75
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Villarrica ; FTIR ; SO2 flux ; DOAS ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2013-02-15
    Print ISSN: 1529-6466
    Electronic ISSN: 1943-2666
    Topics: Geosciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2016-01-18
    Description: iFit is a new intensity-based retrieval algorithm for direct fitting of measured UV spectra, specifically developed for use in volcanology. It has been designed with a focus on minimising processing of the measured spectra prior to analysis. Here, we report a detailed presentation of the iFit algorithm, and test it in 4 case studies, examining clear sky spectra, SO2 calibration cell experiments and volcanic SO2 and BrO retrievals from traverse measurements performed on Mt. Etna volcano, Italy. We show that the major source of fit error in the intensity fitting come from air mass factor independent solar spectrum errors, which are, however, easily characterised and removed by dividing the measured spectrum by a pre-calculated solar spectrum residual. Furthermore, we have quantified the magnitude of the flat spectrum in two spectrometers, and shown that this spectrum is strongly spectrometer dependent but temperature independent, opening the possibility for robust analysis and and BrO without the need for temperature stabilisation of quantification of both SO2 the spectrometer. We find that iFit can be robustly and easily applied to traverse measurements of volcanic plumes, producing bias-free profiles of SO2 , and high quality SO2 /BrO ratios without the need for clear sky background spectra. Fit residuals are typically pure instrumental noise when the residual solar spectrum is removed. We believe that the iFit approach, which avoids the need for a clear sky spectrum and which achieves noise-limited fits, is ideally suited to the automated analysis of spectra produced by networks of scanning UV spectrometers around volcanoes.
    Electronic ISSN: 1867-8610
    Topics: Geosciences
    Published by Copernicus on behalf of European Geosciences Union.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...