Remote sampling of water from Yugama crater lake at Kusatsu-Shirane volcano, Japan, was performed using a drone. Despite the high altitude over 2000 m above sea level, our simple method successful in retrieving 250 mL sample water. The procedure presented here is easy for any researcher to follow who operates drone without additional special apparatus. We compare sampled by with that hand site where regular samplings have previously been carried out. Chemical concentrations and stable...

Definite increases in the components ratios of CO2/H2O, CO2/H2S, CO2/CH4 and He/CH4 were observed at fumarolic gases from Owakudani geothermal area located center Hakone volcanic caldera (Honshu Island, Japan), synchronized with earthquake swarm 2015. Such variations due to dominance a magmatic component over hydrothermal component, suggesting was produced by injection into system. The CO2/H2O ratio gas estimated be 0.0045 before swarm, which increased up 0.013 during likely pressurization...

At Kusatsu-Shirane volcano Japan, the intense seismic activity took place in 2014 and 2018. To investigate relationship between chemistry of fumarolic gas, gas samples have been repeatedly analyzed. A monotonic decrease CO2/H2O, He/H2O N2/H2O ratios since July to November 2017 suggests decline magmatic component. On contrary CH4/H2O ratio significantly increased during seismically quiet period, suggesting reduced condition hydrothermal system favoring formation CH4. The high N2/He period...

We repeatedly measured isotopic compositions of noble gases and CO2 in volcanic sampled at six fumaroles around the Kusatsu-Shirane volcano (Japan) between 2014 2021 to detect variations reflecting recent activity. The synchronous increases 3He/4He some suggest an increase magmatic gas supply since 2018. is also supported by temporal 3He/CO2 ratios carbon CO2. 3He/40Ar* (40Ar*: 40Ar) show significant period high ratios. variation may reflect changes magma vesicularity. Therefore, ratio...

Chemical and stable isotopic compositions (δD, δ18O, δ34S) of non-volcanic hot spring waters around the Miocene Kofu granitic complex surrounding basin in South Fossa Magna region central Honshu, Japan, were analyzed order to investigate water-rock interactions determine origin sulfur characteristics their trace amounts SO42- ion. All water samples from rocks classified as Na-Alkalinity (Alk) type, whereas volcanic Na-Alk, Na-SO4, Na-SO4·Cl·Alk, Ca-SO4 types. The originated meteoric water,...

Abstract Direct sampling and analysis of fumarolic gas was conducted at Ebinokogen Ioyama volcano, Japan, between December 2015 July 2020. Notable changes in the chemical composition gases related to volcanic activity included a sharp increase SO 2 H concentrations May 2017 March 2018. The analyses 2018 immediately preceded April eruption volcano. isotopic ratios O revealed process formation. Up 49% high-enthalpy magmatic vapor mixed with 51% cold local meteoric water generate coexisting...

Constituent minerals and water-soluble components of the volcanic ash discharged from eruption Mt. Motoshirane on January 23, 2018, were analyzed to investigate source environment this eruption. The sample included quartz, plagioclase, cristobalite, pyrite, alunite, kaolinite, pyrophyllite; its mineral assemblage suggests that a high-temperature acid alteration zone had been formed in edifice Motoshirane. presence pyrophyllite indicates explosion took place at depth reaching basement rocks...

The major chemical and stable isotopic compositions of hydrogen, oxygen, sulfur (δD, δ18O, δ34S) were analyzed from water samples wells natural springs in the northern foot area Mt. Fuji adjacent Misaka Tanzawa Mountains to investigate origin deep well waters water-rock interactions that affect quality. was considered have originated through mixing meteoric with very small amounts altered seawater had been trapped pore spaces basement rock, so-called green tuff formations. components...

Regular sampling of lake water has been performed at many volcanoes to assess the state volcanic activity. However, it is not clear whether absolute concentrations or, instead, rate changes in are more suitable for such assessments. In this study, we show that temporal an element described by a simple differential equation, assuming volume and chemical processes negligible. The time constants (63% response concentration water) have wide range varying between 20 1,000 days studied Japan,...

On June 29, 2015, a small phreatic eruption occurred in the Owakudani geothermal area on Hakone volcano, central Japan. Ashfall was observed 29 and 30. In this study, constituent minerals, whole-rock composition, water-soluble components of ash sampled at 30 were analyzed to determine source depth hydrothermal condition ash. The sample included smectite, pyrite, tridymite cristobalite, gypsum, anhydrite with plagioclase quartz, indicating that discharged from relatively low-temperature...

Interpreting the triggering mechanisms for phreatic eruptions is a key to improving hazard assessment of crater lakes. Yugama Crater Lake at Kusatsu-Shirane volcano, Japan, site frequent with recent in 1982–83, 1989, and 1996, as well volcanic unrest, including earthquake swarms 2014 2018. To understand magma–hydrothermal interaction beneath Lake, we analyzed lake waters from November 2005 May 2021. From 2012, Cl SO 4 concentrations decreased slowly, suggesting development self-sealing zone...

Earthquake swarms have occurred with volcanism repeatedly at Hakone volcano in Kanagawa prefecture, Japan. In 2015, a phreatic eruption took place about two months after the start of an earthquake swarm. is popular tourist destination. If it possible to forecast early stages swarm whether or not will occur, could contribute preventing disasters involving tourists. At volcano, increases ratio components (CO2/H2S) contained volcanic gas from fumaroles were observed synchronization and ground...

Riverbed sediments from 19 Hayakawa River sites in Hakone Caldera Japan were analyzed for 37 elements, categorized into three groups by location: Group-1 (nine mainstream samples), Group-2 (five tributary samples with somma upstream), and Group-3 central volcanic cones upstream). Principal component analysis (PCA) showed the 3PCs explain approximately 77% of total variance. The first principal (PC1) is derived inverse correlation between Al a group including Na, K, rare earths elements...

Purpose: This study assessed the suitability of groundwater in parts Yaoundé city for drinking and domestic purposes, investigating factors controlling its composition. Materials Methods: Water samples were collected during dry season analyzed physicochemical parameters major ions. Findings: Results showed an acidic aquifer with generally fresh water, dominated by Ca-HCO3, Na-Cl, Ca-NaHCO3, Ca-Cl water types. While most ions within WHO guidelines, nitrates exceeded safe limits samples, some...

Abstract We propose a new reaction device for the microdiffusion analysis of CO 2 in fluid samples from volcanic areas to improve conventional procedure, which requires fixative and good handling skills. To accomplish this, small resin cell sample solution acid (initiator liberation) was devised placed commercially available air-tight glass container with Petri dish form unit. The based on principles manual titration method that uses Ba(OH) as absorbent. Using device, 99.5% recovery,...

We performed stereomicroscopic, X-ray diffraction (XRD), and water-soluble components analyses on volcanic ash discharged from the June 17, 1962 eruption of Yakedake volcano. Ash samples were collected without surface soil rainfall contamination. Pyrite gypsum identified, as well other previously reported constituent minerals, 1,250 mg/kg Cl 10,800 SO 4 components. The presence hydrothermal alteration minerals large amounts indicates that was a phreatic event originated in zone.