Crater Lake Water Research Articles

Oxygen, hydrogen, and sulfur isotope systematics of the crater lake system of Poas Volcano, Costa Rica.

Oxygen, hydrogen, and sulfur isotope data for fluids and minerals associated with the crater lake of Poas Volcano, Costa Rica, are interpreted in the context of the chemical and hydrologic structure of the volcano. Oxygen and hydrogen isotope data were obtained for rain, spring, and river water, low-temperature fumarole condensates, and acid brines collected from the hot crater lake before its disappearance in April 1989. Flank river and spring waters whose solute compositions have been modified by volcanic and hydrothermal activity have, with one exception, isotopic compositions similar to local meteoric water. Acid chloride-sulfate brines of the summit crater lake are extremely enriched in 18O with respect to local meteoric water; in the most enriched brines 18O shifts are greater than 20‰. The 18O shift is related to a kinetic isotope effect associated with the intense evaporation at the surface of the lake. These same brines exhibit only minimal shifts in their D/H ratios. The apparent lack of deuterium fractionation in the brines is attributed to an increase in the flux of isotopically light steam into the crater lake and/or a decrease in the deuterium fractionation factor for evaporation that occurs at the surface of the lake. The decrease in deuterium fractionation is correlated with large increases in lake-brine acidity and dissolved solids concentration that preceded the disappearance of the lake. Sulfur isotope data are presented for H2S and SO2 gas collected from low temperature fumaroles; dissolved sulfate in spring, river, and crater lake waters; and native sulfur and gypsum found in the acid lake and active crater area. ΔSO2-H2S for low temperature gases is approximately 24‰ indicating an equilibration temperature of 165°C. ΔSO2-H2S for low temperature H2S and lake brine sulfate is approximately 23‰, all indicating subsurface equilibration occurred at 265°C. The H2S and native sulfur are both highly depleted in 34S (δ34S = –8 to –11‰). δ34S values of 34S-depleted H2S and 34S-enriched sulfate in lake brine are produced by disproportionation of SO2 released by the shallow magma body. Native sulfur is formed by the oxidation of 34S-depleted H2S by non-sulfur-bearing oxidants such as atmospheric oxygen and ferric iron. Mass-balance calculations indicate that sulfitolysis of polythionic acids could also result in the deposition of significant quantities of native sulfur. Implications of the isotopic composition of present-day fluids observed at Poas Volcano with respect to the isotope systematics of acid-sulfate ore deposits are considered.

Lanthanoid abundances of acidic hot spring and crater lake waters in the Kusatsu-shirane volcano region, Japan.

The lanthanoid (Ln) contents of nine hot spring and one crater lake waters in the Kusatsu-shirane volcano region, Japan were measured by neutron activation analysis. The waters examined were all acidic with pH ranging from 1.21 to 4.21. All fourteen naturally occurring Ln's were determined for six waters and at least seven Ln's were determined for the other waters. The Ln contents were as a whole at the ppb levels. The Ln patterns obtained by normalization with the Ln contents in Leedey chondrites differed from water to water but were classifiable into two groups; one with a relative enrichment of the light Ln's and thus showing negative slopes and the other having no or little slope (horizontal patterns). The horizontal patterns were found for the Kusatsu-yubatake and Bandaiko hot spring waters and the Yugama water. The Ln patterns of the waters in the Kusatsu area are explained by considering that the light Ln's are leached from rock by flowing acidic waters faster than the heavy Ln's, that in the Ln distribution between acidic water with high Ln contents and rock the heavy Ln's are relatively more preferentially distributed into the solution phase than the light Ln's are, and in addition that andesitic rocks in the Kusatsu area altered by flowing acidic waters have flatter Ln patterns than those of unaltered ones. It was also found that the fluctuation of the Ln pattern from the expected smooth line was in general larger for the heavy Ln's than for the light Ln's, which could be a manifestation of the tetrad effect.

Determination of thorium and uranium in hot spring and crater lake waters by neutron activation analysis

Determination of Th and U in acidic hot spring and crater lake waters was investigated by neutron activation analysis (NAA). Before neutron irradiation, Th and U were preconcentrated and separated from interfering nuclides such as alkali metals and halogens by coprecipitation with aluminium. Irradiation was carried out in two ways, viz., irradiation with Cd foil wrapping (epithermal NAA) and irradiation without Cd foil wrapping (normal NAA). The final determined values of Th and U were at ppb levels. Higher reliability of the determined values was obtained for Th than for U. It was found that epithermal NAA was more effective for the determination of these two actinides than normal NAA and was more effective for the determination of U than that of Th.

Determination of praseodymium, neodymium and erbium in hot spring and crater lake waters by neutron activation analysis incorporating the standard addition technique

Previously undetermined three rare earth elements (REE's), Pr, Nd and Er, in acidic hot spring and crater lake waters were determined at ppb levels by neutron actavation analysis with the standard addition technique. Errors on final detemined values were 7.1–56%. Combining the present results and the results previously obtained amounts to the determination of all 14 naturally occuring REE's in the waters.

Determination of rare earth elements in hot spring and crater lake waters by epithermal neutron activation analysis

Determination of the rare earth elements (REE's) in acidic hot spring and crater lake waters by neutron activation analysis (NAA), in which activation was performed mostly by epithermal neutrons (epithermal NAA) was investigated. Nine REE's, La, Ce, Sm, Eu, Tb, Ho, Tm, Yb and Lu, out of fourteen naturally existing REE's were determined at ppb levels with satisfactory precision. The epithermal NAA was found to be more effective in the determination of Sm, Tb, Ho and Yb than normal NAA, in which activation was performed mainly by thermal neutrons. Combined use of the epithermal and normal NAA's enabled the determination of eleven REE's, La, Ce, Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb and Lu.

Determination of rare earth elements in hot spring water and crater lake water samples by neutron activation analysis incorporating coprecipitation process using aluminium as a collector

Hot spring water and crater lake water samples were analyzed for their rare earth elements: (REE's) by neutron activation method, which, in the irradiation, sample preparation, incorporated a coprecipitation process in which aluminium was used as a collector. Ten REE's, La, Ce, Sm, Eu, Gd, Tb, Dy, Tm, Yb and Lu, were consequently detected and determined at the ppb level with satisfactory precision. It was shown that the aluminium coprecipitation is effective in enhancing concentrations of the REE's and reducing the amounts of interfering nuclides before neutron irradiation.

Quenching and liquid chromatographic determination of polythionates in natural water

Polythionates in highly acidic, crater-lake water have been determined by ion-chromatography and high-performance microbore liquid chromatography. The first technique allows the determination of tri-, tetra- and pentathionate in excess of 10 ppm, and the second allows analysis for tetra-, penta- and hexathionate in excess of 0.2 ppm. The methods for preserving polythionates in natural solutions are also discussed. The recommended procedures for storage are to add hydroxylamine hydrochloride to sample solutions or to exclude atmospheric oxygen by using Winkler oxygen-determination bottles, followed by storage in a refrigerator at 5°.

Correlation of Volcanic Activity with Sulfur Oxyanion Speciation in a Crater Lake

The Yugama crater lake at Kusatsu-Shirane volcano, Japan, contains nearly 2200 tons (2800 parts per million) of polythionate ions (Sn O(6)(2-), where n = 4 to 9). Analytical data on lake water sampled before and during eruptions in 1982 showed that the concentrations of polythionates decreased and sulfate increased in response to the preeruption activities of the subaqueous fumaroles. These changes were observed 2 months before the first phreatic explosion on 26 October 1982. The monitoring of polythionates and sulfate in crater lake water is a promising means of anticipating potential volcanic eruption hazards.

67B. Prediction of volcanic eruption by monitoring polythionates in crater-lake water.(Abstracts of Papers Presented at the Spring Meeting of the Society)

67B. Prediction of volcanic eruption by monitoring polythionates in crater-lake water.(Abstracts of Papers Presented at the Spring Meeting of the Society)

Crater Lake revisited: Concentration changes in water column radionuclides, 1967 to 1981

A small‐scale resampling of Crater Lake water was carried out in 1981. Water from three depths (surface, 3 m, and 14 m) was obtained and analyzed for 3H, 90Sr, 137Cs, and plutonium. The results indicate that 3H and 90Sr quantitatively remain in the water column and that the lake is well mixed. Twenty‐five percent of the 137Cs and more than 90% of the plutonium has been removed from the water column, presumably into the sediment.

Mechanism of the 1979 explosive eruption of soufriere volcano, St. Vincent

The vulcanian explosive phase of the Soufriere of St. Vincent in 1979 occurred when magma penetrated the water-logged 1971–1972 lava island in the center of the crater lake. The 13-day period of explosive and volcanoseismic activity ceased when the crater lake had dried up and subsequent activity was restricted to quiet lava extrusion. The explosive phase produced 15.5 × 10 5m 3 dense rock equivalent (D.R.E.) of new magma and 22 × 10 6m 3 D.R.E. of lithic material from the 1971–1972 island, whereas the following extrusive phase produced a dome of volume 47 × 10 6 m 6.Considerations of the energetics of the explosive eruption indicate that the available heat content of the new magma (5.8 × 10 16 J) was not sufficient to account for the observed phenomena, including evaporation of the 25 × 10 6 m 3 crater lake, and that additional 8 × 10 16 J of heat remaining in the 1971–1972 lava mass are required to drive the eruption plumes. Field relations, the high proportion of lithic material and the energy relations of the eruption are consistent with a phreato-magmatic eruption mechanism involving a three-way interaction of the 1971–1972 lava mass, crater lake water and magma, as a consequence of net-veining and thermally induced hydraulic fracturing of the water-logged 1971–1972 lava island by new magma in 1979.

Phreatic eruptions of Ruapehu: April 1975

Abstract A major phreatic eruption occurred in Ruapehu Crater Lake, North Island, New Zealand, at 1975 April 24d, 03h 59m, N.Z.S.T. Only nine minutes of volcanic-seismic activity preceded the eruption, but crater dilation had been measured by a geodetic survey two weeks earlier. Bad weather prevented observation of the eruption. At least 1· 6 + 106 m3 of Crater Lake water and lake floor deposits were ejected, final lake level falling by more than 8 m. Hot ballistic ejecta fell up to 1· 6 km upwind from the vent; fine ash fell from a narrow plume extending at least 115 km to south-east. Major floods passed down river valleys draining Ruapehu summit, damaging ski installations, bridges, and hydro-electric power scheme constructions. Because of the time of the eruption, no loss of life occurred. Solid ejecta consisted largely of lake floor deposits, some thermally metamorphosed to sanidinite facies (> 750°c) mineral assemblages, plus minor scoriaceous lava blocks. Steam production by self-sustained reaction ...

Ecological studies on crater lakes in West Cameroon. Debundsha Lake

Cape Debundsha receives 10 m (400 inches) of rain per year, and the water of the small crater lake on the cape has one of the lowest conductivities in Africa (11–13 µmho/cm/20 C). The lake has a maximum depth of 13·5 m. At the time of our visit in April 1972 the lake was stratified with a depletion of oxygen in the hypolimnion. The phytoplankton was dominated by Botryococcus, and the zooplankton was dominated by the ostracod Oncocypris debundshae. Both these organisms are closely associated with the surface film. Other zooplankters included Thermocyclops hyalitws, and in deeper water during the daytime the larvae of Chaoborus ceratopogones.The fauna of the lake includes 12 species of testacean rhizopods, six species of rotifers, two oligochaetes, one snail, seven crustaceans, 15 insects and three acarines. Of the last group two species were new to science and one had been found only once previously. The ectoproct polyzoan, Lophopodella carteri, is recorded for the first time from West Africa, and the second time from Africa. The general impression of the fauna is one of sparseness, with an unusually high proportion of larval Odonata.

Spectral variations in the volume scattering function at large angles in natural waters

The quasi-single-scattering approximation in which a δ function replaces the forward portion of the volume scattering function is applied to radiative transfer in the ocean. Immediately beneath the surface, the product of the reflectance R and the downwelling irradiance-attenuation coefficient K(−) is equal to an integral of the volume scattering function in the backward direction weighted by a geometrical factor. Spectral variations of the volume scattering function are revealed in K(−)R; this is used to examine the wavelength dependence of scattering in two very different natural waters. In the clear water of Crater Lake, the backscattering is proportional to λ−3 (λ = wavelength), whereas the turbid, productive waters of San Vicente Reservoir show a complex dependence of backscattering on wavelength, which is associated with anomalous dispersion due to the 670-nm absorption band of the chlorophyll that is contained in the suspended phytoplankton.

Effects of volcanism on water chemistry, Deception Island, Antarctica

Analyses are presented of waters from crater lakes on Deception Island and from coastal sea waters which were collected during a period of intense fumarolic activity and increasing seismic activity prior to the 1969 eruption. Major-component analysis shows all samples to be slightly modified sea waters. However, crater-lake waters are almost saturated with silica and all waters contain high levels of manganese (30 to 2,420 μg/1), suggesting a significant volcanic source for these elements.

Optical Properties of Clear Natural Water*

This paper reports spectroradiometric data obtained with a highly developed double monochromator at three depths and above the surface, at Crater Lake, Oregon. These data have been used to calculate spectral values of the diffuse-attenuation coefficient, and the underwater-reflectance function of Crater Lake water, which is a natural analog of distilled water. The data have also been used to calculate the spectral and total energy available for visibility or photosynthesis and the radiant power absorbed per unit volume, all at a number of depths to 600 m. The data and calculations are reported at 5-nm intervals in the wavelength region 350 nm to 700 nm.

The Blue Water of Crater Lake

IN the Cascade Mountains, Oregon, is the remarkable Crater Lake. It is about six miles long by four miles wide and lies within a volcanic crater the cliffs of which are 500-2,000 ft. high. Its depth in places is nearly 2,000 ft. It has no visible outlet, yet its water is fresh and is said never to freeze, although the surface is about 6,000 ft. above sea-level. It was discovered by white men in 1853, and was called the Deep Blue Lake. Seen from the rim of the crater, the water shades from turquoise blue along the shallow borders to darkest prussian blue in the deeper parts. From a boat, the colour deepens to dark indigo. Cloud shadows and wind flurries produce great variety in the appearance of the surface, but the main sensation produced in the eye of the observer is one of “unbelievable blueness”. Dr. Edison Pettit, working on behalf of the National Academy of Sciences and the National Park Services, has recently completed a study of the reason for this extraordinary depth of blue (News Service Bulletin (School Edition); Carnegie Institution of Washington, 4, No. 4). He finds that the water has no special colour of its own, but that it is exceptionally free from suspended matter; such scattering of light as occurs in its depths is mainly from the water molecules, and is therefore deep blue. The degree of clarity is almost that of specially prepared dust-free water. The scattered light from dust-free water is blue at all angles; that from Crater Lake water is white only for a comparatively narrow forward angle, and at all other angles is blue.

On the Color of Crater Lake Water

On the Color of Crater Lake Water

Composition of the Water of Crater Lake, Oregon.

Composition of the Water of Crater Lake, Oregon.