Augustine Volcano Research Articles

Leachability of uranium and other elements from freshly erupted volcanic ash

A study of leaching of freshly erupted basaltic and dacitic air-fall ash and bomb fragment samples, unaffected by rain, shows that glass dissolution is the dominant process by which uranium is initially mobilized from air-fall volcanic ash. Si, Li, and V are also preferentially mobilized by glass dissolution. Gaseous transfer followed by fixation of soluble uranium species on volcanic-ash particles is not an important process affecting uranium mobility. Gaseous transfer, however, may be important in forming water-soluble phases, adsorbed to ash surfaces, enriched in the economically and environmentally important elements Zn, Cu, Cd, Pb, B, F, and Ba. Quick removal of these adsorbed elements by the first exposure of freshly erupted ash to rain and surface water may pose short-term hazards to certain forms of aquatic and terrestrial life. Such rapid release of material may also represent the first step in transportation of economically important elements to environments favorable for precipitation into deposits of commercial interest. Ash samples collected from the active Guatemalan volcanoes Fuego and Pacaya (high-Al basalts) and Santiaguito (hornblende-hypersthene dacite); bomb fragments from Augustine volcano (andesite-dacite), Alaska, and Heimaey (basalt), Vestmann Islands, Iceland; and fragments of “rhyolitic” pumice from various historic eruptions were subjected to three successive leaches with a constant water-to-ash weight ratio of 4:1. The volcanic material was successively leached by: (1) distilled-deionized water (pH = 5.0–5.5) at room temperature for 24 h, which removes water-soluble gases and salts adsorbed on ash surfaces during eruption; (2) dilute HCl solution (pH = 3.5–4.0) at room temperature for 24 h, which continues the attack initiated by the water and also attacks acid-soluble sulfides and oxides; (3) a solution 0.05 M in both Na,CO, and NaHCO, (pH = 9.9) at 80°C for one week, which preferentially dissolves volcanic glass. The first two leaches mimic interaction of ash with rain produced in the vicinity of an active eruption. The third leach accelerates the effect of prolonged contact of volcanic ash with alkaline ground water present during ash diagenesis.

Volcanic Contribution of Chlorine to the Stratosphere: More Significant to Ozone Than Previously Estimated?

Earlier estimates of the chlorine emission from volcanoes, based upon evaluations of the preeruption magmatic chlorine content, are too low for some explosive volcanoes by a factor of 20 to 40 or more. Degassing of ash erupted during 1976 by Augustine Volcano in Alaska released 525 x 10(6) kilograms of chlorine (+/- 40 percent), of which 82 x 10(6) to 175 x 10(6) kilograms may have been ejected into the stratosphere as hydrogen chloride. This stratospheric contribution is equivalent to 17 to 36 percent of the 1975 world industrial production of chlorine in fluorocarbons.

Plume dynamics, thermal energy and long-distance transport of vulcanian eruption clouds from Augustine Volcano, Alaska

Abstract Augustine, an island volcano in Lower Cook Inlet, southern Alaska, erupted in January, 1976, after 12 years of dormancy. By April, when the eruptions ended, a new lava dome had been extruded into the summit crater and about 0.1 km3 of pyroclastics had been deposited on the island, mainly as pyroclastic debris avalanches and pumice flows. The ventclearing phase in January was highly explosive and we have been able to document 13 major vulcanian eruptions. The timing, thermal energy, mass loading of fine particles and the horizontal dispersion of these eruption clouds were determined from radar measurements of cloud height, reports of pilots flying in plumes, satellite photography, seismic records and infrasonic detection of air waves. A lower estimate of the mass of fine (r The vulcanian eruption clouds stayed intact for at least 700 km downwind. Satellite images in both visible and infrared wavebands, showing the Gulf of Alaska just after sunrise on January 23, reveal a series of puffs strung out downwind from the volcano, 20–30 km in diameter and with their tops at altitudes of about 8 km, overlying a continuous plume at altitude 4 km. Each puff corresponded to a seismically and infrasonically timed eruption. A substantial portion of the material injected into the atmosphere between January 22 and 25 was rapidly transported by the subpolar jet stream through southwestern Canada and the western United States, then northeast across the States into the Atlantic. The clouds were observed passing over Tucson, Arizona, on January 25 at an elevation of 7 km. Several of the eruptions penetrated into the stratosphere. Sun photometer measurements, taken at Mauna Loa, Hawaii, six weeks after the eruption, showed an increased stratospheric optical thickness of 0.01 (wavelength 0.5 μm), which decayed in about 5 months. The maximum column mass loading of the veil was 4–10 × 10−7 g cm−2. The mass of the veil, spread-ever a fourth of the earth's surface, is 10 to 100 times larger than can be accounted for by assuming that injected ash and converted sulfate particles from the 13 main Augustine eruptions are the only components contributing to the stratospheric turbidity observed at Mauna Loa.

The enrichment of volatile elements in the atmosphere by volcanic activity: Augustine volcano 1976

Samples of atmospheric particulate material were collected in the plume of Augustine volcano in February 1976 by using the high‐volume filtration system aboard the National Center for Atmospheric Research Lockheed Electra. The samples were analyzed for 38 elements by a combination of instrumental neutron activation analysis and atomic absorption spectrometry. The results indicate that the volatile elements Zn, Cu, Au, Pb, As, Cd, Cl, Br, Se, Sb, Hg, and S are enriched in the atmospheric samples in relation to bulk ash by factors ranging from 10 to several thousand. The enrichments compare closely with those observed for other volcanic emanations and for background aerosols in remote areas of the earth. Samples collected early in the eruption cycle had a much higher quantity of volatile elements in relation to ash than the later samples, indicating a substantial change in the emission of volatiles with time and eruptive cycle.

Particles in the Eruption Cloud from St. Augustine Volcano

Particles in the Eruption Cloud from St. Augustine Volcano

Response : Particles in the Eruption Cloud from St. Augustine Volcano

<i>Response</i> : Particles in the Eruption Cloud from St. Augustine Volcano

Observations of a Nuée Ardente from the St. Augustine Volcano

A series of aerial photographs were obtained of a nuée ardente produced by the February 8, 1976 eruption of the St. Augustine volcano, Alaska. The nuée ardente reached a maximum velocity of 50 m s−1 while descending the steeper (∼1∶3) slope of the volcano. It later slowed to a velocity of 6 m s−1 as it traversed the gentler slope (∼1∶25) at the base of the volcano, where it formed a deposit. The nuée ardente appeared to originate with the collapse or penetration of a newly formed dome, rather than the collapse of a vertical eruption column. Fluidization by fine particles in the nuée ardente probably contributed to its mobility.

Combined use of lidar and numerical diffusion models to estimate the quantity and dispersion of volcanic eruption clouds in the stratosphere: Vulcán Fuego, 1974, and Augustine, 1976

Methods are described for estimating the quantity and dispersion on a global scale of the material injected into the stratosphere by a violent volcanic eruption by using a combination of lidar measurements of stratospheric aerosols and a previously described two-dimensional atmospheric dispersion model with the initial volcanic cloud as the ‘source function’ (Cadle et al., 1976). The technique involves comparing the lidar data with model predictions normalized by using data of various kinds obtained after the Gunung Agung eruption in Bali in 1963. In this paper we show that the estimates for the Fuego eruption of 1974 can be made equally well by comparing model and lidar measurements of peak stratospheric concentrations or the total masses within a range of altitudes in a column above the place where the lidar measurements were made. The lidar data previously reported have been extended to several months following the eruption of Augustine volcano in Alaska during January and February 1976. The results indicate that the Augustine eruption must have injected no more than one fiftieth of the amount of material into the stratosphere that was injected by Agung and confirm the previous finding (Cadle et al., 1976) that Fuego injected one fifth of the amount injected by Agung.

Eruptions of the St. Augustine Volcano: Airborne Measurements and Observations

Airborne measurements of the effluents from the St. Augustine volcano obtained during a 10-day period of activity showed that aerosol was ejected at the rate of about 10(5) kilograms per second during brief eruptions (3 to 8 minutes). Steadier emissions contained much more water vapor and gaseous sulfur but less aerosol mass. A nuée ardente (glowing avalanche) produced by one eruption reached a maximum average speed of about 50 meters per second.

The 1976 eruption of Augustine Volcano, Alaska

The 1976 eruption of Augustine Volcano, Alaska

Mesozoic Fossils from Augustine Island, Cook Inlet, Alaska: GEOLOGIC NOTES

Upper Jurassic and Upper Cretaceous fossiliferous marine strata are present on the south flank of Augustine Volcano. The Late Jurassic rocks contain Buchia concentrica as well as the first reported Buchia piochii (Gabb) from the Cook Inlet area, indicating a possible correlation with the upper part of the Naknek and lower part of Staniukovich Formations of the Alaska Peninsula. The Upper Cretaceous rocks contain fossils of Campanian to Maestrichtian age and are correlative with the Kaguyak Formation of the Katmai area.

Microearthquakes at St. Augustine Volcano, Alaska, Triggered by Earth Tides

Microearthquake activity at St. Augustine volcano, located at the mouth of Cook Inlet in the Aleutian Islands, has been monitored since August 1970. Both before and after minor eruptive activity on 7 October 1971, numerous shallow-foci microearthquake swarms were recorded. Plots of the hourly frequency of microearthquakes often show a diurnal peaking of activity. A cross correlation of this activity with the calculated magnitudes of tidal acceleration exhibited two prominent phase relationships. The first, and slightly more predominant, phase condition is a phase delay in the microearthquake activity of approximately 1 hour from the time of maximum tidal acceleration. This is thought to be a direct microearthquake-triggering effect caused by tidal stresses. The second is a phase delay in the microearthquake activity of approximately 5 hours, which correlates well with the time of maximum oceanic tidal loading. Correlation of the individual peaks of swarm activity with defined components of the tides suggests that it may be necessary for tidal stressing to have a preferential orientation in order to be an effective trigger of microearthquakes.