Origin of methane-rich natural gas in Japan: formation of gas fields due to large-scale submarine volcanism
53
Citation
62
Reference
10
Related Paper
Citation Trend
Keywords:
Fumarole
Forearc
Volcanic Gases
Natural gas field
Cite
Citations (0)
The ground uplift that occurred at Phlegrean Fields during the “crisis” of 1982–1984 is analyzed by taking into account the volcanological history of the area, the available geophysical information, and the data obtained through our systematic geochemical study. The chemical composition of the products of a unique historical eruption in A.D. 1538 displays a strong evolved character and fits the hypothesis of a progressive reduction in size of the magma body, which probably behaved as a closed system. The bicarbonate contents of the thermal waters in the area has increased with time, suggesting inputs of carbon dioxide into the shallow aquifers. Temperatures at the fumaroles have not changed for at least a hundred years, indicating that boiling aquifer at depth feeds the surface manifestations. Significant variations in the ratios H 2 S/CO 2 and H 2 /N 2 observed at the same time suggest that both the rate of ground uplifting and the increase of seismic energy release may be related to the fluctuation of a convective flow from a deep heat source. Tectonic activity can modify the permeability of deep structures and thereby trigger increased activity in surface manifestations.
Fumarole
Cite
Citations (33)
Fumarole
Volcanic Gases
Isotopes of strontium
Cite
Citations (150)
Sulphur speciation in volcanic gases acts as a major redox buffer, and H 2 S/SO 2 ratios represent a valuable indicator of magmatic conditions and interactions between magmatic and hydrothermal fluids. However, measurement of H 2 S/SO 2 even by direct sampling techniques, is not straightforward. We7 report here on application of a small ultraviolet spectrometer for real‐time field measurement of H 2 S and SO 2 concentrations, using open‐path and extractive configurations. The device was tested at fumaroles on Solfatara and Vulcano, Italy, in November 2002. H 2 S concentrations of up to 220 ppmm (400 ppmv) were measured directly above the Bocca Grande fumarole at Solfatara, and H 2 S/SO 2 molar ratios of 2 and 2.4, respectively, were determined for the ‘F11’ and ‘F0’ fumaroles at Vulcano. In comparison with other optical techniques capable of multiple volcanic gas measurements, such as laser and FTIR spectroscopy, this approach is considerably simpler and cheaper, with the potential for autonomous, sustained high‐time resolution operation.
Fumarole
Volcanic Gases
Cite
Citations (88)
Geosphere, August 2010, v. 6, p. 397-429, doi:10.1130/GES00515.1, Supplemental Tables - Excel file of four supplemental tables. File size is 1.5 MB.
Cite
Citations (0)