Search results for "Soil co2 flux"
showing 6 items of 6 documents
Diffuse soil CO2 degassing from Linosa island
2014
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Understanding Degassing Pathways Along the 1886 Tarawera (New Zealand) Volcanic Fissure by Combining Soil and Lake CO2 Fluxes
2019
CO2 flux measurements are often used to monitor volcanic systems, understand the cause of volcanic unrest, and map sub-surface structures. Currently, such measurements are incomplete at Tarawera (New Zealand), which erupted with little warning in 1886 and produced a ∼17 km long fissure. We combine new soil CO2 flux and C isotope measurements of Tarawera with previous data from Rotomahana and Waimangu (regions also along the 1886 fissure) to fingerprint the CO2 source, understand the current pathways for degassing, quantify the CO2 released along the entire fissure, and provide a baseline survey. The total CO2 emissions from the fissure are 1227 t⋅d–1 (742–3398 t⋅d–1 90 % confidence interval…
Effects of soil gas permeability and recirculation flux on soil CO2 flux measurements performed using a closed dynamic accumulation chamber
2009
Abstract Dynamic accumulation chamber methods have been extensively used to estimate the total output of CO2 released from active volcanic area. In order to asses the performance and reliability of a closed dynamic system several tests were carried out with different soil permeabilities and soil CO2 fluxes. A special device was used to create a constant one-dimensional CO2 flux through a soil column with a known permeability. Three permeabilities were investigated, ranging between 3.6 × 10− 2 and 3.5 × 10 μm2, as were several CO2 fluxes (ranging between 1.1 × 10− 6 and 6.3 × 10− 5 kg m− 2 s− 1). The results highlight that the accuracy of soil CO2 flux measurements strictly depends on the so…
Continuous monitoring of hydrogen and carbon dioxide at Mt Etna
2013
article i nfo This study assessed the use of an H2 fuel cell as an H2-selective sensor for volcano monitoring. The resolution, repeatability, and cross-sensitivity of the sensor were investigated and evaluated under known laboratory conditions. A tailor-made device was developed and used for continuously monitoring H2 and CO2 at Mt Etna throughout 2009 and 2010. The temporal variations of both parameters were strongly correlated with the evolution of the volcanic activity during the monitoring period. In particular, the CO2 flux exhibited long-term variations, while H2 exhibited pulses immediately before the explosive activity that occurred at Mt Etna during 2010.
Total (fumarolic + diffuse soil) CO2 output from Furnas volcano
2015
Furnas volcano, in São Miguel island (Azores), being the surface expression of rising hydrothermal steam, is the site of intense carbon dioxide (CO2) release by diffuse degassing and fumaroles. While the diffusive CO2 output has long (since the early 1990s) been characterized by soil CO2 surveys, no information is presently available on the fumarolic CO2 output. Here, we performed (in August 2014) a study in which soil CO2 degassing survey was combined for the first time with the measurement of the fumarolic CO2 flux. The results were achieved by using a GasFinder 2.0 tunable diode laser. Our measurements were performed in two degassing sites at Furnas volcano (Furnas Lake and Furnas Villag…
Anomalous soil CO 2 degassing in relation to faults and eruptive fissures on Mount Etna (Sicily, Italy)
1998
The relationships between soil gas emissions and both tectonic and volcano-tectonic structures on Mt. Etna have been studied. The investigation consisted of soil CO2 flux measurements along traverses orthogonal to the main faults and eruptive fissures of the volcano. Anomalous levels of soil degassing were found mainly in coincidence with faults, whereas only 49% of the eruptive fissures were found to produce elevated CO2 soil fluxes. This result suggests that only zones of strain are able to channel deep gases to the surface. According to this hypothesis, several previously unknown structures are suggested. Based on our geochemical data, new structural maps of different areas of Etna are p…