Sulfur dioxide and particles in quiescent volcanic plumes from Poás, Arenal, and Colima Volcanos, Costa Rica and Mexico

Abstract

Measurements of SO2 emission rates and concentrations and of particle distribution, size, shape, and composition were made in quiescent volcanic plumes emitted into the troposphere from Poás and Arenal volcanos, Costa Rica, and Colima volcano, Mexico. SO2 emission rates were 700±180 metric tons per day (t/d) for Poás, 210±30 t/d for Arenal, and 320±50 t/d for Colima. The concentrations of SO2 calculated from the COSPEC/lidar data were 5–380 ppb. Concentrations of SO2 measured directly by flame photometry were 10–250 ppb. Particles collected in the plumes with a quartz crystal microbalance impactor were mostly less than 3 μm in diameter and consisted of droplets of dilute sulfur‐bearing solutions and minor amounts of larger silicate particles coated with a sulfur‐bearing film or crust. Total particle concentrations were 4.7 μg/m3 for Poás and 18.8 μg/m3 for Colima. Comparison of concentrations of SO2 in the plumes with gas samples collected at fumaroles on the ground suggests that the plumes are diluted by the atmosphere by factors of up to 105.

The geochemistry of the Keli Mutu crater lakes, Flores, Indonesia.

“…The minimum volcanic element flux of about 30-50 tons S02/day is in the lower range for ac tive, passively degassing arc volcanoes (Casadevall et al, 1984), but the true mass fluxes are larger because these estimates are based on static lake systems. Sinks for sulfur may be seepage and precipitation of native sulfur and gypsum/anhy drite.…”

Fluxes, sizes, morphology and compositions of particles in the Mt. Erebus volcanic plume, December 1983

“…In cases where ash particles are not mantled in acid and the free acid droplets are found mainly in stage 7, the mass in that stage gives a conservative estimate of the acid content in the plume. In most volcanic plumes sampled by this technique (Rose et al, , 1982Chuan et al, 1981 ;Casadevall et al, 1984) it has been possible to isolate the sulfuric acid droplets on a few stages of the instrument so that the acid mass fraction of the total aerosol mass can be determined with an accuracy of ± 25 % or better. If simultaneous SO2 gas and particle measurements are made in a volcanic plume, one can estimate the overall particle flux and also the relative proportions of S present in gas and in acid droplets.…”

Thermal and geochemical signature of Poás Volcano, Costa Rica (MARCH 2009)

“…Andres et al (1992), Casadevall et al (1984), Stoiber et al (1986Stoiber et al ( ), zimmer et al (2004, Barrancos et al (2006) and this work (black diamonds) are shown. Fig.…”

“…The overall low sulphur emission may reflect a decrease of activity after the vigorous volcanic phases observed in the 1980s (e.g., Martínez et al, 2000), when high fluxes (~8 times greater than those recorded starting from the 1990s) were documented (Casadevall et al, 1984;Stoiber et al, 1986;Andres et al, 1992;zimmer et al, 2004). For small plumes, walking-based traverses allow for more detailed recording of volcano degassing signatures.…”

“…In 1981, preceded by a regional earthquake (Rymer et al, 2000), a shallow magma intrusion beneath the dome triggered an increase in fumarole temperatures from 92 to ~1000°C (Casertano et al, 1987) and SO 2 fluxes up to ~700 Mg d-1 (Casadevall et al, 1984;Andres et al, 1992). In June 1987, an intense period of phreatic eruptions began (SMITHSONIAN, 1987).…”