Particles in the fume from the 1967 Kilauea eruption

Abstract

Little has been known about the nature of the particles in the fume that accompanies volcanic eruptions of the Hawaiian and Icelandic types, although at times in the earth's history tremendous amounts of such particles must have been emitted into the atmosphere. The fume from I-Ialemaumau crater of Kilauea volcano was sampled in 1965 and 1966 during the absence of an eruption [Cadle et al., 1967; Cadle, 1967; Cadle et al., 1968]. The particles consisted largely of dilute sulfuric acid droplets containing ammonium ions. The 1967 eruption of Halemaumau crater (Figure 1) provided an opportunity to sample and identify particles in the actual eruption fume. Samples were collected from various points about the crater's edge (including the place where Figure 1 was taken) on November 14 and 15 using a Unico multistage impactor operated with a Gelman battery-driven pump. The impactor was modified slightly to permit impaction into both microscope slides, and electron microscope grids mounted on such slides and covered with a film of silicon monoxide.Almost all the particles were collected on the last stage of the impactor, indicating that the diameters were less than about 5/•. Examination of the samples with an optical microscope showed that the particles were largely hygroscopic, water-miscible droplets, plus a few mainly acicular, solid particles. At least two, and possibly more, types of acicular particles were present. Some were water-soluble and optically isotropic, and others were optically anisotropic. Refractive indices of some were measured using a series of immersion liquids of different refractive indices. These particles had a refractive index of about 1.524 and were probably CaSO, ß 2I-I20. Other acicular material was soluble in the Cargille immersion liquids and was probably sulfur. Tests with Nessler's reagent and with an aqueous solution of barium chloride showed the presence of ammonium and sulfate ions, respectively, in the gross collected material.

Volcanic emissions of halides and sulfur compounds to the troposphere and stratosphere

“…During the last few years, scientists here at the National Center for Atmospheric Research have been determining the physical and chemical nature of the particles in volcanic eruption clouds [Cadle and Frank, 1968;Cadle et al, 1967Cadle et al, , 1969Cadle et al, , 1973Cadle and Blifford, 1971 ] and also the nature and concentrations of particles and trace gases in the stratosphere [Cadle, 1972;Lazrus et al, 1971Lazrus et al, , 1972Lazrus and Gandrud, 1974]. Furthermore, an estimate was made of the annual quantities of sulfur compounds emitted to the atmosphere by volcanoes [Kellogg et al, 1972].…”

Comparison of particles in the fume from eruptions of Kilauea, Mayon, and Arenal volcanoes

“…Naughton (personal communication, 1968) has stated that, although ammonia is unstable, the ammonium ion is stable under magmatic conditions. Other explanations for the presence of ammonium ion were suggested by Cadle and Frank [1968].…”

“…Table 1 shown in Figure 2 together with an electron micrograph of deposited ash particles. A comparison of these electron micrographs with those of particles from the Kilauea fume [Cadle and Frank, 1968] reveals that every type of particle observed in the Kilauea fume can be found in Mayon fume. However, particles that appear to be ash, as well as some small spheres not found in the ash, are observed among the Mayon particles but not among the Kilauea particles.…”

“…The midget impinger, which collects the particles in a few millimeters of distilled water, has been described by Kusnetz [1966]. The impactor and pump had been used in the previous investigation [Cadle and Frank, 1968].…”

Journal of Research of the U. S. Geological Survey, 1973, volume 1, issue 6

“…Accordingly, the preemption contents of sulfur and chlorine may have been unusually high. Alternatively, the reticulite may have provided adsorption traps for sulfur and chlorine present in the fume cloud, either as gases or liquid droplets (Cadle and Frank, 1968).…”