Deep Crustal Fluid Upwelling through Structural Pathways Observed from Non-active Volcanic Regions, Western Kumamoto, Japan

2021 ◽  
Author(s):  
Takahiro Hosono ◽  
Chikashige Yamanaka
Keyword(s):  
Cation Exchange ◽  
Hot Spring ◽  
Saline Water ◽  
Tectonic Setting ◽  
Western Coast ◽  
Volcanic Origin ◽  
Low Concentration ◽  
Dissolved Carbon ◽  
Crustal Fluid ◽  
Structural Weakness

Abstract Natural springs containing volcanic and magmatic components occur along major volcano-seismotectonic regions over the worlds. However, features of the deep-originated waters were less documented from regions where active volcanic and magmatic activities are not distributed. To characterize the presence of deep fluids of non-volcanic origin 28 groundwater samples (~ 1,230 m deep) were collected from hot spring sites located at western coast of Kumamoto where the typical subduction related magmatisms are absent. The samples were measured for dissolved ion concentrations and stable isotope ratios (δ2HH2O, δ18OH2O, δ13CDIC and δ34SSO4) that were compared with data of 33 water samples from vicinity surface systems. The groundwaters were classified into three types based on major hydrochemistry: high Cl− fluid, low concentration fluid, and high HCO3− fluid. Our dataset suggests that the high Cl− fluid was formed by saline water mixing with aquifer waters of meteoric origin and subsequently evolved by reverse cation exchange. The low concentration fluid is identical to regional aquifer water of meteoric origin that was subjected to cation exchange. The high HCO3− fluid showed the highest HCO3− concentrations (~ 3,888 mg/l) with the highest δ13CDIC (-1.9‰). Taking recent geophysical mappings under the study area, we suggest that dissolved carbon was of mantle origin and fluids with high HCO3− generated in lower crust were transported towards surface through structural weakness under open tectonic setting. Observed δ2HH2O and δ18OH2O shifts support this scenario. The occurrence of deep crustal fluid discharges was sporadic and limited in surface in the study area. Their impacts on surface hydrological systems were minimal except few locations.

scholarly journals Origins and pathways of deeply derived carbon and fluids observed in hot spring waters from non-active volcanic fields, western Kumamoto, Japan

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Takahiro Hosono ◽  
Chikashige Yamanaka
Keyword(s):  
Cation Exchange ◽  
Hot Spring ◽  
Saline Water ◽  
Tectonic Setting ◽  
Western Coast ◽  
Data Set ◽  
Low Concentration ◽  
Dissolved Carbon ◽  
Structural Weakness ◽  
Structural Deformations

AbstractNatural springs containing volcanic and magmatic components occur in association with these activities. However, features of deeply originated fluids and solutes were less documented from fields, where active volcanic and magmatic activities are not distributed. To characterize the presence of deep components and identify their major pathways 28 groundwater samples (~ 1230 m deep) were collected from hot spring sites located at western coast of Kumamoto, southwestern Japan, where the typical subduction related magmatisms are absent. The samples were measured for dissolved ion concentrations and stable isotope ratios (δ2HH2O, δ18OH2O, δ13CDIC and δ34SSO4) that were compared with data of 33 water samples from vicinity surface systems. The groundwaters were classified into three types based on major hydrochemistry: high Cl− fluid, low concentration fluid, and high HCO3− fluid. Our data set suggests that the high Cl− fluid was formed by saline water mixing with aquifer waters of meteoric origin and subsequently evolved by reverse cation exchange. The low concentration fluid is identical to regional aquifer water of meteoric origin that was subjected to cation exchange. The high HCO3− fluid showed the highest HCO3− concentrations (~ 3,888 mg/l) with the highest δ13CDIC (up to − 1.9‰). Based on our carbon mixing model and observed δ2HH2O and δ18OH2O shifts, it is suggested that dissolved carbon of mantle origin and small fraction of fluids generated in deep crust were transported towards surface through structural weakness under open tectonic setting. These deeply derived components were then mixed with waters in the surface systems and diluted. Their impacts on surface hydrological systems were limited in space except few locations, where deeply connected pathways are anticipated along active structural deformations.

scholarly journals Dissolved Carbon Dioxide Sensing Platform for Freshwater and Saline Water Applications: Characterization and Validation in Aquaculture Environments

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5513
Author(s):  
J.P. Mendes ◽  
L. Coelho ◽  
B. Kovacs ◽  
J.M.M.M. de Almeida ◽  
C.M. Pereira ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Limit Of Detection ◽  
Saline Water ◽  
Light Emitting Diode ◽  
Limit Of Quantification ◽  
Acid Media ◽  
Dissolved Carbon ◽  
Sensing Platform ◽  
Dissolved Carbon Dioxide ◽  
Colorimetric Indicator

A sensing configuration for the real-time monitoring, detection, and quantification of dissolved carbon dioxide (dCO2) was developed for aquaculture and other applications in freshwater and saline water. A chemical sensing membrane, based on a colorimetric indicator, is combined with multimode optical fiber and a dual wavelength light-emitting diode (LED) to measure the dCO2-induced absorbance changes in a self-referenced ratiometric scheme. The detection and processing were achieved with an embeded solution having a mini spectrometer and microcontroller. For optrode calibration, chemical standard solutions using sodium carbonate in acid media were used. Preliminary results in a laboratory environment showed sensitivity for small added amounts of CO2 (0.25 mg·L−1). Accuracy and response time were not affected by the type of solution, while precision was affected by salinity. Calibration in freshwater showed a limit of detection (LOD) and a limit of quantification (LOQ) of 1.23 and 1.87 mg·L−1, respectively. Results in saline water (2.5%) showed a LOD and LOQ of 1.05 and 1.16 mg·L−1, respectively. Generally, performance was improved when moving from fresh to saline water. Studies on the dynamics of dissolved CO2 in a recirculating shallow raceway system (SRS+RAS) prototype showed higher precision than the tested commercial sensor. The new sensor is a compact and robust device, and unlike other sensors used in aquaculture, stirring is not required for correct and fast detection. Tests performed showed that this new sensor has a fast accurate detection as well as a strong potential for assessing dCO2 dynamics in aquaculture applications.

Nouvelle interpretation des fractures des eruptions laterales de l'Etna; consequences pour son cadre tectonique

2001 ◽  
Vol 172 (4) ◽  
pp. 455-467 ◽  
Author(s):  
Jean-Claude Bousquet ◽  
Gianni Lanzafame
Keyword(s):  
Stress Field ◽  
Large Scale ◽  
Tectonic Setting ◽  
Lateral Spreading ◽  
Volcanic Edifice ◽  
Geophysical Data ◽  
Normal Faults ◽  
Complex Situation ◽  
Volcanic Origin ◽  
Flank Eruptions

Abstract Mt Etna is cut by numerous fractures (fissures and faults) of very different origin and orientation. They have been used to define the activity and the tectonic setting of the volcano. After a discussion of the proposed tectonic models for Etna, an examination of the fractures, which are linked to the high flank eruptions, was carried out based on the geological and geophysical studies of the recent eruptions (1983, 1989, 1991-93). All of these surface breaks are of strictly volcanic origin; they open and advance very slowly, in relation to the propagation of the dyke, as well as its width and depth from the volcano surface. If the dyke summit is not too far from the surface (about 200-300 m), fissures and normal faults, arranged in a graben, appear. When the dyke intersects the slope of the volcano, a flank eruption follows. Therefore, these fractures do not have a tectonic or volcano-tectonic origin: they do not cut the entire volcanic edifice, and thus cannot be used to define the rift-zones nor to characterise the tectonic regime controlling the functioning of Etna. They give information on the dyke orientation on the slopes of the volcanic edifice and cannot be used as significative markers of extension [Frazzetta and Villari, 1981; Kieffer 1983a and b; Monaco et al., 1997]. The simultaneous opening of radial fractures, according to various azimuths, is frequent and clearly indicates that, in these cases, the regional stress field is not implicated. But high on Etna, the concentration of flank eruptions, on the eastern side, and the orientation change of the fractures (fig. 6), when they travel away from the summit, have been repeatedly indicated. The repetition of flank eruptions and the azimuth changes can be explained, simply, by the closeness of the Valle del Bove [Murray, 1994], which induces a decrease of the confinement pressure. The dyke emplacements of the summit eruptions cause an eastward displacement of the higher part of Etna. Marine geophysical data indicate that this volcano is, however, not the site of a large scale lateral spreading to the Ionian sea. Consequently, an eastward detachment is present only on the superior part of the volcano (figs. 1B and 7C). In fact, an up to 100 m high and oversteepened east-facing scarp, between the towns of Vena and Presa, extends towards the south for some kilometers [Lanzafame et al., 2000]. It is made up of volcanic rocks affected by strong brecciation. Inverse faults are found in front of the scarp. The base of this one is found at the level of the pre-Etnean clays, which would have helped the displacement of the volcanics. The studies on the tectonic setting in which Etna is located has called the attention of numerous researchers. From the earliest studies, the presence of numerous normal faults has supported the idea that this volcano, as many others, is active in an extensional regime. The most recent geological and geophysical data show a more complex situation. Deep under Etna (more than 10 km), a compressive field (sigma 1 N-S) is present according to focal mechanisms [Cardaci et al.; 1990; Ferrucci et al., 1993; Cocina et al., 1997]. More superficially, instead, extension is usual. The importance of the weight of the volcanic edifice, in the spatial (horizontal and vertical) modification of the compressive stress field, must still be clarified. It is very clear, in any case, that Etna cannot be explained by an extensional regime or kinematics in extension [Monaco et al., 1997] using normal faults, which form during the flank eruptions.

scholarly journals Preparation of ¹⁸F-NaF radiopharmaceuticals using home-made automatic synthesis module at Hanoi Irradiation Center

2019 ◽  
Vol 9 (1) ◽  
pp. 41-49
Author(s):  
Manh Thang Tran ◽  
Van Vinh Mai ◽  
Thi Tam Dam ◽  
Quang Anh Nguyen ◽  
Thi Thu Hien Le ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Saline Water ◽  
Isotonic Saline ◽  
Radiochemical Yield ◽  
Clinical Tests ◽  
Skeletal Scintigraphy ◽  
Natural Distribution ◽  
Automatic Synthesis ◽  
Pet Ct

The aim of this study is to prepare 18F-NaF radiopharmaceutical using a home-madeautomatic synthesis module consisting of hardware and software which was made by a researcherteam of Hanoi Irradiation Center, HIC, Hanoi, Vietnam. Fluorine-18 isotopes produced in cyclotron KOTRON13 were transferred to the module and radioactive cation impurities were first removed by cation exchange on a carboxymethyl cation exchange (CM) cartridge, and then 18F- ion were trapped by a quaternary methyl ammonium anion exchange (QMA) cartridge. Finally, 18F- was eluated from the cartridge by isotonic saline water (NaCl 0,9% in water) in the form of 18F-NaF. Time of the preparation process was about 13 minutes. Radiochemical yield of the preparation was as high as 95.5%, in average. The qualities of the product were satisfied the criteria of the United StatesPharmacopoeia (USP38). PET/CT bone scaner (skeletal scintigraphy) pre-clinical tests using of the 18 F-NaF product showed good quality of imaging for the entire skeletal and distribution of the 18F-NaF in the kidney and the bladder agreed with it’s natural distribution.

scholarly journals Geological controls on brine discharge in Itumbula Salt Dam within the Rukwa Rift in Momba District, Tanzania

2021 ◽  
Vol 47 (2) ◽  
pp. 552-567
Author(s):  
Mwita S Maswi ◽  
Octavian Minja ◽  
Chakutema Batwenge
Keyword(s):  
Hot Spring ◽  
Saline Water ◽  
Discharge Rate ◽  
Geophysical Methods ◽  
Chloride Ions ◽  
Bicarbonate Ions ◽  
Porous Formation ◽  
Salt Crystals ◽  
Survey Results ◽  
Magnetic Profile

The Itumbula salt dam of the Rukwa Rift Basin is a depression formed through extraction of spring-derived salt crystals. Brine yield by springs which is the primary cause of significant amounts of salt in the dam required further geological investigations to understand yield controls. In this study, detailed field geological investigations in the salt dam and its surroundings were conducted to ascertain brine discharge controls. These included documentation of lithology and surface manifestations of brine deposition. Geophysical methods (i.e. magnetic and electric surveys) for studying geologic structures associated with brine deposits, and laboratory analysis of cations and anions (e.g. chlorides, bicarbonates or sulphates) essential to characterize composition of waters were also performed. The information on the springs discharge rate was retrieved from the previous studies. The magnetic profile revealed a very low magnetic anomaly across the salt dam, trending NW to SE direction, which is interpreted to be the main structure that controls fluid movements in the dam. Electric resistivity survey results delineated a low resistivity body in the central part of the dam interpreted as porous formation with saline water. Hydro-chemistry of the hot spring brines indicated high levels of sodium and chloride ions contents than magnesium, calcium, potassium, sulphate, and carbonate and bicarbonate ions, interpreted to be mature water with minimal water mixing. The structurally controlled brines of approximately 2.5 kg/s are discharged in the study area. Keywords: Geologic Structures, Brine, Salt Production, Momba, Rukwa Basin.

scholarly journals Membrane Distillation of Saline Water Contaminated with Oil and Surfactants

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 988
Author(s):  
Wirginia Tomczak ◽  
Marek Gryta
Keyword(s):  
High Salinity ◽  
Sea Water ◽  
Saline Water ◽  
Sodium Dodecyl ◽  
Membrane Distillation ◽  
Process Efficiency ◽  
Feed Water ◽  
Permeate Flux ◽  
Low Concentration

Application of the membrane distillation (MD) process for the treatment of high-salinity solutions contaminated with oil and surfactants represents an interesting area of research. Therefore, the aim of this study is to investigate the effect of low-concentration surfactants in oil-contaminated high-salinity solutions on the MD process efficiency. For this purpose, hydrophobic capillary polypropylene (PP) membranes were tested during the long-term MD studies. Baltic Sea water and concentrated NaCl solutions were used as a feed. The feed water was contaminated with oil collected from bilge water and sodium dodecyl sulphate (SDS). It has been demonstrated that PP membranes were non-wetted during the separation of pure NaCl solutions over 960 h of the module exploitation. The presence of oil (100–150 mg/L) in concentrated NaCl solutions caused the adsorption of oil on the membranes surface and a decrease in the permeate flux of 30%. In turn, the presence of SDS (1.5–2.5 mg/L) in the oil-contaminated high-salinity solutions slightly accelerated the phenomenon of membrane wetting. The partial pores’ wetting accelerated the internal scaling and affected degradation of the membrane’s structure. Undoubtedly, the results obtained in the present study may have important implications for understanding the effect of low-concentration SDS on MD process efficiency.

Regional structures influencing the groundwater geochemistry around geothermal springs: A case study from Padiyathalawa, Sri Lanka

2021 ◽  
Author(s):  
Dilshan Bandara ◽  
Thomas Heinze ◽  
Mahinda Premathilake ◽  
Stefan Wohnlich
Keyword(s):  
Sri Lanka ◽  
Hot Spring ◽  
Tectonic Setting ◽  
Shallow Groundwater ◽  
Shear Zones ◽  
Geothermal Water ◽  
Geothermal System ◽  
Flow Paths ◽  
Geothermal Springs ◽  
Distribution Maps

<p>Hydro-geochemistry of groundwater plays an important role in understanding the characteristics of a geothermal system. Mixing zones of geothermal deep waters and shallow groundwater can be identified through chemical distribution maps and help identify geothermal flow paths. The flow paths can be used to calculate the chemical values of the geothermal water leading to a characterization of the heat source. In combination with knowledge about regional structures, the geochemical distribution can further reveal unknown geothermal zones.</p><p>In the present study, the geochemical distribution of the groundwater is studied from samples collected from shallow and deep wells, with special reference to the regional structures present in the terrain. The study area was selected as a 20 • 20 km area centered around the Padiyathalawa hot spring field in Sri Lanka. From the results, two main geochemical anomalous zones are identified, especially with the increased values of electrical conductivity (EC), total dissolved solids (TDS), and Sulphate distribution maps. Those two zones include the hot spring itself as well as an area in ~10 km distance in the NE direction from the hot spring. Both zones are characterized by crosscutting structures of dolerite dykes and shear zones. Due to the shear zones, there are deep-seated fractures facilitating water flow from deeper layers towards the surface. This uprising water mixes with the shallow groundwater, affecting the general geochemical values of the shallow groundwater system.</p><p>Common minerals in Dolerite in Sri Lanka are Pyroxenes, Feldspar, Ilmenite, Magnetite, and Pyrite with minor amounts of other minerals. The increased EC values in both before mentioned zones relate with higher amounts of iron due to dissolution and mixing processes in regions with fractured Dolerite. Similarly, the increased concentration of Sulphates in the groundwater can be related to Pyrite from the fractured Dolerite, as microbial oxidization of Pyrite leads to origin of Sulphates. The increase of TDS can be interpreted as shallow water mixing with deep geothermal water, which contains a higher amount of minerals from the fractured dolerites.</p><p>The similar geochemical anomalies in those two zones can be associated with cross-cutting Dolerite dikes and existing faults in the shear zones at greater depth, subsequently mixing uprising deep geothermal water with shallow groundwater. A similar geochemistry and tectonic setting suggest similar flow paths from the underground and therefore also similar geothermal conditions at both spots. However, due to the rural and remote region, only one of the two before mentioned areas is known as a hot spring field. Thermal signatures dissipate much more quickly in the shallow groundwater than the mineral composition and might not be significant for measurement. Geochemical signatures of groundwater can therefore be a substantial help to locate geothermal springs, identify source mechanisms and characterize fluid flow paths.</p>

scholarly journals Design of Electrochemically Effective Double-Layered Cation Exchange Membranes for Saline Water Electrolysis

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2114
Author(s):  
In Kee Park ◽  
Dong-Hoon Lee ◽  
Chang Hyun Lee
Keyword(s):  
Ion Transport ◽  
Cation Exchange ◽  
Saline Water ◽  
Single Layer ◽  
Water Electrolysis ◽  
Electrochemical Process ◽  
Chemical Degradation ◽  
Design Strategies ◽  
Ohmic Resistance ◽  
Alkaline Conditions

Saline water electrolysis (SWE) is an electrochemical process to simultaneously produce hydrogen (H2), chlorine (Cl2), and sodium hydroxide (NaOH) with high purity levels (e.g., 99.999%) by applying electric power to saline water. The state-of-the art SWE membrane, Flemion®, has excellent chemical resistance to harsh SWE conditions, but still needs to lower its energy consumption by reducing its ohmic resistance to Na+ ion transport. Meanwhile, most of cation exchange membranes (CEMs) have been suffering from chemical degradation under the alkaline conditions, owing to their single layer matrices composed of sulfonic acid moieties, though they show fast Na+ ion transport behavior. Here double-layered SWE membranes were prepared on the basis of design strategies composed of the incorporation of a chemically stable carboxylic acid layer (C layer) via UV irradiation onto one surface of perfluorinated Nafion®212 membrane chosen as one of commercially available CEMs, and the thickness control of the C layer. The resulting membranes showed excellent SWE performances and improved electrochemical service life, when compared with those of Nafion®212 and Flemion®, respectively.

scholarly journals Groundwater geochemistry of the Mt. Vesuvius area: implications for volcano surveillance and relationship with hydrological and seismic signals

2013 ◽  
Vol 56 (4) ◽  
Author(s):  
Cinzia Federico ◽  
Paolo Madonia ◽  
Paola Cusano ◽  
Simona Petrosino
Keyword(s):  
Stress Field ◽  
Water Chemistry ◽  
Saline Water ◽  
Fluid Pressure ◽  
Temporal Variations ◽  
Gas Content ◽  
Geochemical Data ◽  
Data Set ◽  
Dissolved Carbon ◽  
Geochemical Parameters

<p>Geochemical data obtained between 1998 and 2011 at the Mt. Vesuvius aquifer are discussed, focusing on the effects of both the hydrological regime and the temporal pattern of local seismicity. Water samples were collected in a permanent network of wells and springs located in the areas that are mostly affected by the ascent of magmatic volatiles, and their chemical composition and dissolved gas content were analyzed. As well as the geochemical parameters that describe the behavior of groundwater at Mt. Vesuvius, we discuss the temporal distribution of volcano-tectonic earthquakes. The seismological data set was collected by the stations forming the permanent and mobile network of the Istituto Nazionale di Geofisica e Vulcanologia - Osservatorio Vesuviano (INGV-OV). Our analysis of seismic data collected during 1998-2011 identified statistically significant variations in the seismicity rate, marked by phases of decreasing activity from October 1999 to May 2001 and increasing activity from August 2004 to mid-2006. The water chemistry shows peculiar patterns, characterized by a changeable input of CO<span><sub>2</sub></span>-rich and saline water, which must be related to either a changing stress field or an increased input of CO<span><sub>2</sub></span>-rich vapor. The water chemistry data from 1999 to 2003 account for both higher fluid pressure (which induced the seismic crisis of 1999 that peaked with a 3.6-magnitude earthquake in October 1999) and the increased input of CO<span><sub>2</sub></span>-rich fluids. The highest emission of CO<span><sub>2</sub></span> from the crater fumaroles and the corresponding increase in dissolved carbon in groundwater characterize the phase of low seismicity. The termination of the phase of intense deep degassing is associated with a change in water chemistry and a peculiar seismic event that was recorded in July 2003. All these seismic and geochemical patterns are interpreted according to temporal variations in the regional and local stress field.</p>

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