A colorimetric and geochemical study of the coloration factor of hyper-acid active crater lakes

Onda, Yuuji; Ohsawa, Shinji; Takamatsu, Nobuki

doi:10.3739/rikusui.64.1

Cited by 15 publications

(24 citation statements)

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“…This indicates that particles larger than 0.7 lm contribute to the absorption and scattering in the lake. In addition, the c(k) of filtrates under 0.1 lm was almost 0 m -1 , which means the following: (1) the small particles (\0.1 lm), which cause the Rayleigh scattering observed by Ohsawa et al (2002) and Onda et al (2003), do not exist in the lake, and (2) the dissolved matter, such as ferrous ions (observed by Onda et al 2003), do not contribute to the absorption of light in the water body (i.e., a d (k) = 0 m -1 ). Figure 5 shows the absorption spectra of TSS (a p (k)), non-phytoplanktonic particles (a n (k)) and phytoplankton (a ph (k)) at St. 1 and 2 ( Fig.…”

Section: Resultsmentioning

confidence: 98%

“…The results showed that the coloration was caused by Rayleigh scattering of aqueous colloidal silica particles with 0.1-0.45-lm diameter. Onda et al (2003) investigated the cloudy emerald green hue of Yugama crater lake on Mt. Shirane, Japan, and reported that the water color is due to the optical interaction among Rayleigh scattering and Mie scattering by colloidal sulfur particles causing blue and cloudy white colors, respectively, and absorption by dissolved ferrous ions causing the green color.…”

Section: Introductionmentioning

confidence: 99%

“…The colors are mainly due to the high concentrations of mineral ions that originated from hydrothermal waters (Oue et al 1998;Ohsawa et al 2002;Onda et al 2003). Ohsawa et al (2002) investigated the blue coloration of a hydrothermal pond in Beppu, Japan, using qualitative colorimetric analysis and performed synthesis experiments to reproduce the blue color.…”

Section: Introductionmentioning

confidence: 99%

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Simulation of water colors in a shallow acidified lake, Lake Onneto, Japan, using colorimetric analysis and bio-optical modeling

Oyama

Shibahara

2009

Limnology

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Lake Onneto has unusually brilliant water colors, such as blue-green, green, and greenish yellow. We investigated the coloration mechanism in this lake by measuring the radiometric water color and inherent optical properties (IOPs), such as attenuation, absorption, and scattering coefficients of color-producing agents (CPAs) in the lake. The hue of the water body was determined using colorimetric analysis. In addition, the radiometric water color of the lake was simulated using bio-optical modeling. Results showed that the hues of the water body were different between two sampling stations (blue-green and green at 3.1 and 5.5 m of bottom depth, respectively). However, the total suspended solids (TSS) concentrations were almost identical between the two stations (0.47 and 0.42 mg l -1 , respectively). In addition, the attenuation and absorption coefficients showed that the CPAs in the water body were only inorganic suspended solids (ISS) more than 0.7 lm in diameter, and specific CPAs, such as dissolved mineral ions and aqueous colloids, were not observed in the lake. Simulation of the radiometric water color showed that the radiation around 600 nm of wavelength (yellow region) steeply increased with decreasing bottom depth, indicating that the water colors of Lake Onneto are strongly governed by the light reflection from yellowish bottom sediments.

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Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Simulation of water colors in a shallow acidified lake, Lake Onneto, Japan, using colorimetric analysis and bio-optical modeling

Oyama

Shibahara

2009

Limnology

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“…1e). Based on the coloration mechanism of the active crater lakes proposed by Onda et al (2003), this slight color change from blue-green to green suggested that Fe 2? concentration, which is the cause of green, had increased and/or colloidal sulfur suspension in the lake water, which is the cause of blue, had diminished.…”

Section: Introductionmentioning

confidence: 98%

“…Their white turbidity is attributable to suspension of elemental sulfur, but blue-green coloration mechanisms have remained unclear. Recently, Onda et al (2003) demonstrated that the lake color is a mixed blue and green color from a study carried out in 2000 at Japanese active crater lakes: Yudamari at Aso volcano and Yugama at Kusatsu-Shirane volcano. The green color is attributable to absorption of sunlight by dissolved ferrous ions (Fe 2?…”

Section: Introductionmentioning

confidence: 98%

Color change of lake water at the active crater lake of Aso volcano, Yudamari, Japan: is it in response to change in water quality induced by volcanic activity?

et al. 2009

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One feature of volcanic lakes influenced by subaqueous fumaroles existing at lake bottoms (called active crater lakes) is the remarkable color of their waters: turquoise or emerald green. The active crater lake named Yudamari at Mt. Nakadake of Aso volcano, Japan, takes on a milky pale blue-green. The particular blue component of the lake water color results from Rayleigh scattering of sunlight by very fine aqueous colloidal sulfur particles; the green component is attributable to absorption of sunlight by dissolved ferrous ions. An objective color observation conducted during 2000-2007 revealed that the lake water color changed from blue-green to solid green. The disappearance of the blue ingredient of the water color will result in diminution of aqueous colloidal sulfur from chemical analyses of lake waters sampled simultaneously. The aqueous sulfur is produced by the reaction of sulfur dioxide and hydrogen sulfide supplied from subaqueous fumaroles. However, its production efficiency decreases by domination of sulfur dioxide in the subaqueous fumarolic sulfur gas species with increasing subaqueous fumarolic temperature. The disappearance of blue ingredients from the blue-green color of the lake water may be attributed to activation of subaqueous fumarole activity.

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Brownish discoloration of the summit crater lake of Mt. Shinmoe-dake, Kirishima Volcano, Japan: volcanic–microbial coupled origin

et al. 2014

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A colorimetric and geochemical study of the coloration factor of hyper-acid active crater lakes

Cited by 15 publications

References 0 publications

Simulation of water colors in a shallow acidified lake, Lake Onneto, Japan, using colorimetric analysis and bio-optical modeling

Simulation of water colors in a shallow acidified lake, Lake Onneto, Japan, using colorimetric analysis and bio-optical modeling

Color change of lake water at the active crater lake of Aso volcano, Yudamari, Japan: is it in response to change in water quality induced by volcanic activity?

Brownish discoloration of the summit crater lake of Mt. Shinmoe-dake, Kirishima Volcano, Japan: volcanic–microbial coupled origin

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