The migration of magma towards the surface in a volcano is usually accompanied by the release of gas that was previously dissolved in the magma itself. In an open conduit volcano, most of the gas escapes through the main conduits of the volcano and then through the craters. However, a significant proportion (approximately 10%) of the total quantity of gas can escape laterally through faults and fractures that are normally present in the flanks of a volcano. Therefore, increases in the amount of gas emitted usually indicate the initial stages of magmatic migration towards the surface. Furthermore, the type of gas that is released at the surface can provide information on the level of volcanic activity. The chemical and isotopic composition of the soil gas is the result of varying degrees of physical-chemical interaction between gas in deep magmatic fluids and more superficial (mainly groundwater). Normally, the higher the flow of volcanic gas that escapes through the soil, the lower is the interaction with surface not magmatic fluids. In turn, high gas flows indicate the arrival and accumulation of new magma rich in surface levels of gas in storage within the volcano, and thus suggest a greater potential for a new volcanic eruption.
In the study of volcanoes, the magna, geochemical and geophysical phenomena, the study of the isotopic composition of H2O and CO2 gases and magmatic hydrothermal vents can be done easily with the LGR analyzers Water Vapor Isotope Analyzer, LGR LGR Carbon Dioxide Isotope Analyzer and Methane Isotope Analyzer.
“Soil Flux Package”
There is now a complete package including all the tools needed to Soil Flux; see “Special Products” to download the brochure for this product.