A5079270945- Atmospheric and Environmental Gas Dynamics
- Geological and Geochemical Analysis
- Atmospheric Ozone and Climate
- Seismology and Earthquake Studies
- earthquake and tectonic studies
- Methane Hydrates and Related Phenomena
- Geochemistry and Geologic Mapping
- Atmospheric chemistry and aerosols
- CO2 Sequestration and Geologic Interactions
- Geology and Paleoclimatology Research
- Earthquake Detection and Analysis
- Spectroscopy and Laser Applications
- Radioactivity and Radon Measurements
- Seismic Waves and Analysis
- Color perception and design
- Marine and coastal ecosystems
- Bioactive Compounds and Antitumor Agents
- Estrogen and related hormone effects
- Air Quality Monitoring and Forecasting
- Groundwater and Isotope Geochemistry
- Gas Sensing Nanomaterials and Sensors
- Landslides and related hazards
- Chromatography in Natural Products
- Mycobacterium research and diagnosis
- Gaze Tracking and Assistive Technology
The University of Tokyo
2014-2024
Rigaku (Japan)
2023
Kyoto University
2023
Association for the Development of Earthquake Prediction
2023
Panasonic (Japan)
2016-2019
Tokyo University of Science
1993-2018
Geophysical Center
2014
National Institute of Information and Communications Technology
2008
Earthquake Engineering Research Institute
2002-2008
SO 2 flux is widely monitored on active volcanoes as it gives a window into the hidden, subsurface magma dynamics. We present here new approach to monitoring using ultraviolet imaging of volcanic plume through carefully chosen filters produce images column amount. The camera heralds breakthrough in both our ability measure at unprecedented frequencies (2 Hz) and accuracy, thanks application correlation techniques determine wind speed directly from whole profile simultaneously. In this paper...
Magmatic carbon dioxide (CO2) degassing has been documented before the 31 March 2000 eruption of Usu volcano, Hokkaido, Japan. Six months eruption, an increase in CO2 flux was detected on summit caldera, from 120 (September 1998) to 340 metric tons per day 1999), followed by a sudden decrease 39 June 2000, 3 after eruption. The change and seismic observations suggests that advective processes controlled gas migration toward surface. at caldera could be due rapid release during ascending...
A phreatic eruption of Mt. Ontake, Japan, started abruptly on September 27, 2014, and caused the worst volcanic calamity in recent 70 years Japan. We conducted plume surveys using an electric multirotor unmanned aerial vehicle to elucidate conditions Ontake's plume, which is flowing over 3000 m altitude. gas composition, sulfur dioxide flux thermal image measurements a particle sampling were carried out for three field campaigns November 20 21, June 2, 2015. Together with results manned...
We report the quantitative evaluation of UV scattering effect on SO 2 emission rate measurement by compact spectrometer system. Plume spectra were obtained simultaneously at three measuring points with different distance to volcanic plume. The apparent absorbance decreases increasing plume and attenuation becomes stronger shorter wavelength bands. In addition, intensity depends column concentration. underestimation measured caused leads rate. was not significant any band (<±10%) 0.6 km...
Research Article| March 01, 2011 Global CO2 emission from volcanic lakes Nemesio M. Pérez; Pérez * 1Environmental Division, Instituto Tecnológico y de Energías Renovables (ITER), 38611 Granadilla Abona, Tenerife, Canary Islands, Spain *E-mail: nperez@iter.es. Search for other works by this author on: GSW Google Scholar Pedro A. Hernández; Hernández German Padilla; Padilla Dácil Nolasco; Nolasco José Barrancos; Barrancos Gladys Melían; Melían Eleazar Padrón; Padrón Samara Dionis; Dionis David...
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...
Enhanced BrO and ClO in the boundary layer associated with ozone destruction have been observed over salt lakes, as well polar layer. Volcanic plumes are a major natural source of atmospheric trace gases, influencing tropospheric stratospheric gas budgets. Though variety volcanic gases investigated was found, there is still little information on other halogen oxides (e.g. ClO) effects ozone. The current belief that contain has not quantified to date. Here we report successful remote...
A telescope‐attached FT‐IR spectral radiometer was applied for remote measurement of chemical composition the volcanic gas Unzen volcano, Japan, which started erupting in November 1990. The observations were carried out at site about 1.3 km away from gas‐emitting region volcano March and July 1992. Absorption features SO 2 (V l ) HCl identified column amounts plume estimated using a nonlinear least‐squares method. /HCl ratio range between 0.7 1.8 both observations. This is first ground‐based...
[1] Multiple volcanic observations conducted at Mt. Asama, Japan, provide evidence of a link between single very-long-period (VLP) seismic pulses and gas emissions. SO2 flux measurements were on 2 June 2009, when Asama was producing ash-free eruptions with VLP pulses. Gas bursts from vent the crater bottom following provided an excellent opportunity to examine relation directly. The emission for each eruption calculated by integrating high temporal data obtained imaging system subtracting...
All available SO 2 flux data for 32 years (1975–2006) of Japanese volcanoes, accounting about 10% the world's arc were compiled to evaluate temporal variation each volcano and estimate time‐averaged flux. The revealed that 6 volcanoes (Tokachi, Asama, Aso, Sakurajima, Satsuma‐Iwojima, Suwanosejima volcanoes) out 17 significantly degassing usually contributed more than 94% total annual was 2.2 Tg a −1 , which includes intense Miyakejima after 2000, raised figure from 1.4 indicating single...
Volcanic gas from an inaccessible fumarole at Aso volcano, Japan, was recently measured with a Fourier Transform InfraRed (FT‐IR) spectral radiometer. Absorption features of CO, COS, CO 2 , SO and HCl were identified in the volcanic plume spectra. This is first time five components are detected simultaneously by remote technique. Based on CO/CO ratio 2.6 × 10 −3 equilibrium temperature estimated to be 750° ± 120°C.
A soil gas and CO 2 efflux survey was carried out at Hakkoda, north Japan, to investigate the spatial distribution origin of which caused accidental death three Japanese soldiers on 12 July 1997. In study area, no fumarolic and/or thermal activity is observed. Chemical composition from areas with high effluxes (>5,000 g m −2 d −1 ) contents (>15 vol %) indicate a strong deep sourced contribution for , whereas air saturated water suggested rest discharged gases, are mainly released...
We have determined SO2 concentration in fumarolic gas released from the summit crater of Asama volcano, Japan, using an infrared spectral radiometer installed a site about 4 km away summit. During observation period 31 October to November 1991, weak activities with height less than 100 m were observed intermittently. The spectrum just above showed slight absorption due rotational bands associated v, vibration (1151 cm–1) molecule. Compared standard gas, this corresponds roughly column amount...
Abstract The thermal activity of a magmatic–hydrothermal system commonly changes at various stages volcanic activity. Few studies have provided an entire picture the such over eruptive cycle, which is essential for understanding subsurface heat transport process that culminates in eruption. This study quantitatively evaluated sequence associated with two phreatic eruptions 2021 Aso volcano. We estimated plume-laden discharge rates and corresponding H 2 O flux during 2020–2022 by using simple...
Remote FT-IR measurements of volcanic plume Mt. Iwodake, Satsuma-Iwojima volcano, Japan, were carried out in October 1996 to understand chemistry the especially characteristics fluorine-bearing species plume. The SO2/HCl molar ratio was about 4, that is larger than high-temperature gases. high content SO2 suggested be caused by sulfur combustion crater. An average SiF4/HF 0.57 observed for plume, which one order magnitude higher previously reported ratio. result shows SiF4 an important and...
Continuous measurements of soil CO2 flux are useful for understanding degassing processes and monitoring volcanic activities. Recent studies at many volcanoes have revealed that variations significantly influenced by environmental parameters as well processes. In this study, we conducted continuous in the flank Nakadake cone, Aso volcano, Japan, from January 2016 to November 2017. The results our observations during an active period before after a large phreatomagmatic eruption on 8 October...
Abstract Sulfur dioxide (SO 2 ) emission rate observations were made at Sakurajima volcano, Japan, to quantify the relationship between SO and inflation prior Vulcanian explosions. The explosions associated with precursory events preceded by decreases in rates 10–60 min. amounts of accumulated gas calculated using time series rate. increases strain records before showed a positive correlation. volume increase deformation source was comparable order magnitude as volcanic gas. results suggest...