Volcanic Hot Springs Research Articles

Rapid Alkalization in Lake Inawashiro, Fukushima, Japan: Implications for Future Changes in the Carbonate System of Terrestrial Waters

The global carbon cycle, one of the important biogeochemical cycles controlling the surface environment of the Earth, has been greatly affected by human activity. Anthropogenic nutrient loading from urban sewage and agricultural runoff has caused eutrophication of aquatic systems. The impact of this eutrophication and consequent photosynthetic activity on CO2 exchange between freshwater systems and the atmosphere is unclear. In this study, we focused on how nutrient loading to lakes affects their carbonate system. Here, we report results of surveys of lakes in Japan at different stages of eutrophication. Alkalization due to photosynthetic activity and decreases in PCO2 had occurred in eutrophic lakes (e.g., Lake Kasumigaura), whereas in an acidotrophic lake (Lake Inawashiro) that was impacted by volcanic hot springs, nutrient loading was changing the pH and carbon cycling. When the influence of volcanic activity was stronger in the past in Lake Inawashiro, precipitation of volcanic-derived iron and aluminum had removed nutrients by co-precipitation. During the last three decades, volcanic activity has weakened and the lake water has become alkalized. We inferred that this rapid alkalization did not result just from the reduction in acid inputs but was also strongly affected by increased photosynthetic activity during this period. Human activities affect many lakes in the world. These lakes may play an important part in the global carbon cycle through their influence on CO2 exchange between freshwater and the atmosphere. Biogeochemical changes and processes in these systems have important implications for future changes in aquatic carbonate systems on land.

Finite Difference Tomography of Crustal Velocity Structure Beneath Tengchong, Yunnan Province

Abstract:This work applies the finite difference tomographic method to invert P‐wave velocity structure beneath the Tengchong area using earthquake data from a temporary network and other permanent stations, and analyzes the magmatic activity of Tengchong volcanoes and the deep structural genesis of the Longling M7.3/M7.4 earthquakes. The results show the velocity structure of the crust in this area has a pronounced heterogeneity. The lower velocities in the shallow subsurface are caused by unconsolidated basin deposits, Cenozoic volcanic deposits, fluid fractures and hot springs. The high‐velocity zone at 5∼15 km depth probably represents cooled and solidified magmatic intrusions or less volatile ultramafic remnants. The low‐velocity structure in the deep crust indicates molten or semi‐molten magma. It is probable that the magmatic activity beneath volcanoes and magma intrusions in the deep crust of the Longling earthquake zone are from the same magmatic hearth area, which is the main area of the present magmatic activities. A strongly lateral heterogeneity is observed in the Longling earthquake zone. The east of the Nujiang fault belt and the west of the Longling fault belt are characterized by high velocity, implying large strain strength of rocks, which are the main carriers of stress accumulation. The low‐velocity anomalies between the two faults extend to lower crust, probably caused by magmatic intrusions in the deep crust. The magmatic activity in this area is controlled clearly by the Longling fault and the Nujiang fault. The Longling M7.3 and M7.4 earthquakes occurred near the velocity boundary beneath the faults. The main reasons for the strong earthquakes in the Longling area inlcude the heterogeneity of stress accumulation caused by the lateral variation of the crustal medium strength, the deep magmatic aggregation and dynamic actions.

Medical Insight into the Hot Springs according to Comparisons of the Chemical Compositions of the Hot Springs in Tokyo 23 Wards with those of the Volcanic Hot Springs

Medical Insight into the Hot Springs according to Comparisons of the Chemical Compositions of the Hot Springs in Tokyo 23 Wards with those of the Volcanic Hot Springs

Genome-Scale Reconstruction and Analysis of the Metabolic Network in the Hyperthermophilic Archaeon Sulfolobus Solfataricus

We describe the reconstruction of a genome-scale metabolic model of the crenarchaeon Sulfolobus solfataricus, a hyperthermoacidophilic microorganism. It grows in terrestrial volcanic hot springs with growth occurring at pH 2–4 (optimum 3.5) and a temperature of 75–80°C (optimum 80°C). The genome of Sulfolobus solfataricus P2 contains 2,992,245 bp on a single circular chromosome and encodes 2,977 proteins and a number of RNAs. The network comprises 718 metabolic and 58 transport/exchange reactions and 705 unique metabolites, based on the annotated genome and available biochemical data. Using the model in conjunction with constraint-based methods, we simulated the metabolic fluxes induced by different environmental and genetic conditions. The predictions were compared to experimental measurements and phenotypes of S. solfataricus. Furthermore, the performance of the network for 35 different carbon sources known for S. solfataricus from the literature was simulated. Comparing the growth on different carbon sources revealed that glycerol is the carbon source with the highest biomass flux per imported carbon atom (75% higher than glucose). Experimental data was also used to fit the model to phenotypic observations. In addition to the commonly known heterotrophic growth of S. solfataricus, the crenarchaeon is also able to grow autotrophically using the hydroxypropionate-hydroxybutyrate cycle for bicarbonate fixation. We integrated this pathway into our model and compared bicarbonate fixation with growth on glucose as sole carbon source. Finally, we tested the robustness of the metabolism with respect to gene deletions using the method of Minimization of Metabolic Adjustment (MOMA), which predicted that 18% of all possible single gene deletions would be lethal for the organism.

Single Archaeal Species Caught Splitting into Two Distinct Groups

A single archaeal species, Sulfolobus islandicus, from an isolated volcanic hot spring in Kamchatka, Russia, is at the point of diverging into two new species, according to microbiologist Rachel Whitaker from the University of Illinois in Urbana-Champaign and her collaborators at the University of California, Davis, and Oxford University in the United Kingdom. Their findings, apparently the first observed instance of sympatric speciation—one lineage becoming two—in a microorganism, provide an illuminating glimpse of how strains in the same niche can diverge. Details appear in the February 2012 PLoS Biology 10(2):e1001265 (doi:10.1371/journal.pbio. e1001265).

Chemical weathering, river geochemistry and atmospheric carbon fluxes from volcanic and ultramafic regions on Luzon Island, the Philippines

We investigated rates of chemical weathering of volcanic and ophiolitic rocks on Luzon Island, the Philippines. Luzon has a tropical climate and is volcanically and tectonically very active, all factors that should enhance chemical weathering. Seventy-five rivers and streams (10 draining ophiolites, 65 draining volcanic bedrock) and two volcanic hot springs were sampled and analyzed for major elements, alkalinity and 87Sr/ 86Sr. Cationic fluxes from the volcanic basins are dominated by Ca 2+ and Mg 2+ and dissolved silica concentrations are high (500–1900 μM). Silica concentrations in streams draining ophiolites are lower (400–900 μM), and the cationic charge is mostly Mg 2+. The areally weighted average CO 2 export flux from our study area is 3.89 ± 0.21 × 10 6 mol/km 2/yr, or 5.99 ± 0.64 × 10 6 mol/km 2/yr from ophiolites and 3.58 ± 0.23 × 10 6 mol/km 2/yr from volcanic areas (uncertainty given as ±1 standard error, s.e.). This is ∼6–10 times higher than the current best estimate of areally averaged global CO 2 export by basalt chemical weathering and ∼2–3 times higher than the current best estimate of CO 2 export by basalt chemical weathering in the tropics. Extrapolating our findings to all tropical arcs, we estimate that around one tenth of all atmospheric carbon exported via silicate weathering to the oceans annually is processed in these environments, which amount to ∼1% of the global exorheic drainage area. Chemical weathering of volcanic terranes in the tropics appears to make a disproportionately large impact on the long-term carbon cycle.

The plant-specific TFIIB-related protein, pBrp, is a general transcription factor for RNA polymerase I

TFIIB and BRF are general transcription factors (GTFs) for eukaryotic RNA polymerases II and III, respectively, and have important functions in transcriptional initiation. In this study, the third type of TFIIB-related protein, pBrp, found in plant lineages was characterized in the red alga Cyanidioschyzon merolae. Chromatin immunoprecipitation analysis revealed that CmpBrp specifically occupied the rDNA promoter region in vivo, and the occupancy was proportional to de novo 18S rRNA synthesis. Consistently, CmpBrp and CmTBP cooperatively bound the rDNA promoter region in vitro, and the binding site was identified at a proximal downstream region of the transcription start point. alpha-Amanitin-resistant transcription from the rDNA promoter in crude cell lysate was severely inhibited by the CmpBrp antibody and was also inhibited when DNA template with a mutated CmpBrp-CmTBP binding site was used. CmpBrp was shown to co-immunoprecipitate and co-localize with the RNA polymerase I subunit, CmRPA190, in the cell. Thus, together with comparative studies of Arabidopsis pBrp, we concluded that pBrp is a GTF for RNA polymerase I in plant cells.

Dissimilatory Oxidation and Reduction of Elemental Sulfur in Thermophilic Archaea

The oxidation and reduction of elemental sulfur and reduced inorganic sulfur species are some of the most important energy-yielding reactions for microorganisms living in volcanic hot springs, solfataras, and submarine hydrothermal vents, including both heterotrophic, mixotrophic, and chemolithoautotrophic, carbon dioxide-fixing species. Elemental sulfur is the electron donor in aerobic archaea like Acidianus and Sulfolobus. It is oxidized via sulfite and thiosulfate in a pathway involving both soluble and membrane-bound enzymes. This pathway was recently found to be coupled to the aerobic respiratory chain, eliciting a link between sulfur oxidation and oxygen reduction at the level of the respiratory heme copper oxidase. In contrast, elemental sulfur is the electron acceptor in a short electron transport chain consisting of a membrane-bound hydrogenase and a sulfur reductase in (facultatively) anaerobic chemolithotrophic archaea Acidianus and Pyrodictium species. It is also the electron acceptor in organoheterotrophic anaerobic species like Pyrococcus and Thermococcus, however, an electron transport chain has not been described as yet. The current knowledge on the composition and properties of the aerobic and anaerobic pathways of dissimilatory elemental sulfur metabolism in thermophilic archaea is summarized in this contribution.

Formation of Ammonium from Nitrate During Chemolithoautotrophic Growth of the Extremely Thermophilic Bacterium Ammonifex degensii gen. nov. sp. nov.

A novel, extremely thermophilic bacterium has been isolated from a neutral volcanic hot spring. The gram-negative, rod-shaped cells were motile and exhibited a complex cell wall composed of murein and a surface protein layer covered by a surface coat. The core lipids consisted of non-phytanyl mono- and diethers and of fatty acid esters. Growth occurred between 57 and 77 degrees C (opt.: 70 degrees C), pH 5.0 and 8.0 (opt.: 7.5) and 0 to 1.5% NaCl (opt.: 0.1% NaCl). The new isolate was a strict anaerobe, growing autotrophically by oxidation of hydrogen or formate, reducing nitrate to ammonium. Instead of nitrate, sulfate or sulfur were used as electron acceptors and H2S was formed as final product. Pyruvate was fermented to acetate, CO2, and hydrogen. The GC-content of the DNA was 54 mol%. On the basis of its 16S rRNA sequence, the new isolate represents a new genus, belonging to the "low G+C" subgroup of the gram-positive bacteria. Strain KC4 (DSM 10501) is described as the type strain of a new genus and species, which we name Ammonifex degensii.

Thiosulfate reduction, an important physiological feature shared by members of the order thermotogales

Several members of the order Thermotogales in the domain Bacteria, viz., Thermotoga neapolitana, Thermotoga maritima, Thermosipho africanus, Fervidobacterium islandicum, and Thermotoga strain SEBR 2665, an isolate from an oil well, reduced thiosulfate to sulfide. This reductive process enhanced cellular yields and growth rates of all the members but was more significant with the two hyperthermophiles T. neapolitana and T. maritima. This is the first report of such an occurrence in this group of thermophilic and hyperthermophilic anaerobic bacteria. The results suggest that thiosulfate reduction is important in the geochemical cycling of sulfur in anaerobic thermal environments such as the slightly acidic and neutral-pH volcanic hot springs and oil reservoirs.

Mössbauer studies of first-stage corrosion products on iron powder and corrosion products on highly corroded nails

Magnetic iron powders were treated in solutions containing NaCl or CH 3 COONa as corrosion agents at 298 K and the oxide layers produced on the iron surface were identified by means of Mössbauer spectrometry. The measurement of Mössbauer spectra at various temperatures was useful to assign the chemical species produced on the surface. The spectra consisted of the superparamagnetic doublet peaks of polymorphic forms of FeOOH at room temperature. Highly corroded nails collected from different environments, i.e. sea coast, volcanic hot spring and an inland house, were examined to characterize the atmospheric corrosion products of nails. As a result, it was found that a-FeOOH and γ-Fe 2O 3 were present in every case. β-FeOOH and Fe 3O 4 were detected in nails collected at sea coast, volcanic hot spring and an inland house, respectively. The above results show that chemical pollution in the atmosphere is reflected in the species of corrosion products of nails exposed. Long-time exposure of nails resulted in the formation of γ-Fe 2O 3 and a-FeOOH.

Fire under the sea: the discovery of the most extraordinary environment on earth--volcanic hot springs on the ocean floor

Fire under the sea: the discovery of the most extraordinary environment on earth--volcanic hot springs on the ocean floor

Plumbing the depths

Water Baby: The Story of Alvin. By Victoria A. Kaharl. published by Oxford University Press: 1991. Pp.356. £15, $21.95. Fire Under the Sea: The Discovery of the Most Extraordinary Environment on Earth — Volcanic Hot Springs on the Ocean Floor. By Joseph Cone. published by William Morrow: 1991. Pp.287. $25.

Origin of sulfur species in acid sulfate-chloride thermal waters, northeastern Japan

Acid sulfate-chloride thermal water samples collected together with fumarolic gases from various volcanic areas in northeastern Japan were studied chemically and isotogdically. δ 34S (COT) values of sulfate and hydrogen sulfide from these volcanic hot springs range from +4.0 to +31 and from −15.0 to −2.0% respectively, with δ 34S ys value of +2.5 to +31. The δ 34S of the sulfate in the more saline waters tends to become smaller with increasing ratio of SO 4 to Cl, although the chemical and isotopic composition of acid thermal water within some areas may be altered by secondary processes during the discharge of the thermal waters. This trend can be explained by the reaction of the volcanic gases, having S/Cl of 4 ~ 7 and total sulfur of ~0% in δ 34S, with ground water at 200°C, and/or the removal of sulfide phase depleted in 34S from the acid thermal water formed by the disproportionation of volcanic sulfur. The sulfur species in acid sulfate-chloride thermal water are shown to be volcanic exhalations.

Thermal structure and energy of the Hakone volcano, Japan

The thermal energy balance and the temperature profile of the Hakone volcano are considered quantitatively. Across the Hakone volcano and its surroundings the heat flow values vary from 10−1 to 103 mW/m2, due to thermal conduction and mass flow involving volcanic steam and hot spring discharge. An area with extremely low heat flow is observed in the western side of the caldera showing the presence of percolating meteoric water. The hydrothermal activity is intense in the eastern half of the caldera.

Heat flow measurements in the inlets of southwestern British Columbia

The geothermal heat flux has been measured at 15 sites in the inlets of southwestern British Columbia by using the ocean probe technique. Corrections have been applied for variations in bottom water temperature, sedimentation, thermal refraction by the sediment prism, topography, warm-rim effect, Pleistocene thermal history, uplift, and erosion. The accuracy of the values is about ±0.3 μcal cm−2 s−1 (±13mW m−2). The relative accuracy between the values is about half of this range. The data indicate a pattern of low heat flow from the coast inland about 200 km to the heads of the inlets (13 values average 0.9 μcal cm−2 s−1 or 37 mW m−2). Stations at the heads of two inlets (1.5 μcal cm−2 s−1 or 63 mW m−2) mark the transition to high heat flow further inland (about 2.0 μcal cm−2 s−1 or 84 mW m−2). From west to east the heat flow transition coincides with the first occurrence of recent volcanic centers and hot springs, the transition from high to low Bouguer gravity, and the transition to low deep crustal and upper mantle electrical resistivity and to recent regional uplift. The coast low heat flow is explained partly by low crustal radioactive heat production and in part by the heat sink effect of the cold oceanic Juan de Fuca plate being subducted along the continental margin. The high inland heat flow probably is produced by the upward convective transport of heat by magma and thinning of the lithosphere that occurs when the sinking plate reaches a depth where temperatures are sufficient for partial melting. Low mantle temperature and thus high density in both the continental lithosphere and the underlying subducted oceanic lithosphere under the coast zone explain the high Bouguer gravity and thick crust in this region compared with the low gravity and thin crust inland. To the north of about 51°N where at present there is transform fault motion along the continental margin, there probably was subduction prior to about 10 m.y. ago. The gravity and crustal thickness data suggest that the high density in the subducted oceanic lithosphere has disappeared but that upwelling and a hot thin continental lithosphere persist inland of 200 km from the continental edge.

Characteristics of Geothermal Resources From Geologic and Geochemical Viewpoints in Japan: ABSTRACT

The distribution of thermal areas in Japan is geologically divided into the following units: (1) Neogene Tertiary sedimentary basins, (2) Neogene Tertiary plutonic rock areas, (3) Neogene Tertiary green-tuff areas, (4) Pliocene-Quaternary sedimentary basins, and (5) Quaternary volcanic areas. Among these, the Pliocene-Quaternary sedimentary basins are areas of normal terrestrial heat flow. The Tertiary plutonic rock areas have locally abnormal heat flow, but heat flow from the Tertiary sedimentary basins and green-tuff areas is in general higher than that of normal heat-flow areas. There are about 100 geothermal areas with water temperatures higher than 80°C in the mentioned areas and most of these are distributed in the Quaternary volcanic areas. Some hot springs issuing from the active volcanic areas are characterized by a low pH because of contained hydrochloric acid. These can be called typical volcanic hot springs. To promote geothermal development, the Geological Survey of Japan is carrying on geothermal investigations in 30 promising areas. These investigations commenced last year and will be continued for a period of three years. Exploratory wells will be drilled in the areas selected by detailed surveys. These wells will be financed by governmental special funds commencing this year. The present investigations are being made to find new geothermal areas consisting of hot-water and/or dry-steam systems. However, if a study on the extraction of heat from hot dry rocks is commenced in the near future, the Quaternary dacite areas as well as the active volcanic areas will be selected as promising. End_of_Article - Last_Page 1452------------

Origin of volcanic hot springs

Origin of volcanic hot springs

Massive pyritic deposits related to volcanism, and possible methods of emplacement

Deposits of massive pyrite and pyrrhotite-pyrite occur mainly in volcanic rocks and particularly in the uppermost pyroclastic parts of submarine volcanic piles. Large deposits of massive pyrite and pyrite-sulfur have formed in the recent past and are forming now around fumaroles and volcanic hot springs in Japan and Taiwan. The older but undeformed massive pyrite deposits of Cyprus appear to have formed in the same manner, but largely under submarine conditions. Deposits in deformed rocks, as those at Rio Tinto, Spain, and Shasta county, California, give less positive evidence of origin but appear to be of the same type. Material in volcanic emanations is thought to be in both a molecularly dispersed and a colloidally dispersed state where emanations enter a near-surface submarine environment. Rapid flocculation of colloids and rapid precipitation of material in solution are postulated to occur in sea water or in sea-water-soaked pyroclastic rocks and sediments. Several mechanisms for formation of dense bodies of massive sulfide are suggested, but filtration of the flocculated and precipitated material, with accompanying replacement, appears to be a probable process.

Volcanic Geology, Hot Springs and Geysirs of Iceland

(1951). Volcanic Geology, Hot Springs and Geysirs of Iceland. Norsk Geografisk Tidsskrift - Norwegian Journal of Geography: Vol. 13, No. 3-8, pp. 328-328.