A5033196630- Methane Hydrates and Related Phenomena
- Geological and Geochemical Analysis
- Geology and Paleoclimatology Research
- Atmospheric and Environmental Gas Dynamics
- earthquake and tectonic studies
- Hydrocarbon exploration and reservoir analysis
- Geological and Geophysical Studies
- CO2 Sequestration and Geologic Interactions
- Geochemistry and Geologic Mapping
- Groundwater and Isotope Geochemistry
- Radioactivity and Radon Measurements
- Earthquake Detection and Analysis
- Marine and coastal ecosystems
- Seismic Waves and Analysis
- Atomic and Subatomic Physics Research
- Isotope Analysis in Ecology
- Cryospheric studies and observations
- Seismic Imaging and Inversion Techniques
- Seismology and Earthquake Studies
- High-pressure geophysics and materials
- Calibration and Measurement Techniques
- Spacecraft and Cryogenic Technologies
- Arctic and Antarctic ice dynamics
National Taiwan University
2004-2019
The University of Tokyo
2010-2019
Centre de Recherches Pétrographiques et Géochimiques
2017-2018
Université de Lorraine
2017-2018
Centre National de la Recherche Scientifique
2013-2018
Institute of Earth Sciences, Academia Sinica
2015-2016
Kueishantao is a Holocene volcanic islet (<7,000 yrs) located at NE offshore Taiwan, and tectonically part of western extension the Okinawa Trough. Magmatic activities are considered very active around this area on basis fact that on-land fumaroles submarine hydrothermal systems prevailing currently. Representative bubble gas samples from vents were collected for composition helium isotope analysis. The gases show similar compositions low temperatre in world, i.e., with high CO2 H2S but SO2...
It has been found that Bottom Simulating Reflections (BSRs), which infer the existence of potential gas hydrates underneath seafloor sediments, are widely distributed in offshore southwestern Taiwan.Fluids and gases derived from dissociation hydrates, typically methane enriched, affect composition seawater sediments near venting areas.Hence, concentration become useful proxies for exploration a given area.We systematically collected bottom waters sedimentary core samples dissolved pore-space...
Helium has two natural isotopes which have contrasted, and variable sources sinks in the atmosphere (3He/4Heair = 1.382 ± 0.005 × 10−6). Variations atmospheric helium isotopic composition may exist below typical measurement precision thresholds (0.2 to 0.5%, 2σ). In order investigate this possibility, it is necessary be able consistently measure air with high (below 0.2% We created an purification system that improves isotope precision. By purifying a large quantity of at start cycle we can...
Abstract Methane emission from the geosphere is generally characterized by a radiocarbon-free signature and might preserve information on deep carbon cycle Earth. Here we report clear relationship between origin of methane-rich natural gases geodynamic setting West Pacific convergent plate boundary. Natural in frontal arc basin (South Kanto gas fields, Northeast Japan) show typical microbial with light isotopes, high CH 4 /C 2 H 6 / 3 He ratios. In Akita-Niigata region – which corresponds to...
Giggenbach bottle technique is used to systematically analyze fumarolic gas composition of the Tatun Volcano Group, northern Taiwan.The area quite active hydrothermally and also considered volcanically active.The samples predominantly steam water with CO 2 as dominant component after de-watering.Minor components include sulfur species (mainly H S SO ), N CH 4 .Interestingly, in study area, concentration always much higher than for all measured gases.This result resembles typical low...
Abstract Geochemical monitoring of groundwater in seismically-active regions has been carried out since 1970s. Precursors were well documented, but often criticized for anecdotal or fragmentary signals, and lacking a clear physico-chemical explanation these anomalies. Here we report – as potential seismic precursor oxygen isotopic ratio anomalies +0.24‰ relative to the local background measured groundwater, few months before Tottori earthquake (M 6.6) Southwest Japan. Samples deep located 5...
Hydrothermal plumes above the HAKUREI and JADE sites, two high-temperature hydrothermal vent sites in Izena Cauldron at mid-Okinawa Trough, were investigated order to gain a preliminary understanding of gas geochemical characteristics underlying sites. Three tracers, H2, CH4 δ3He, covary with each other site but only δ3He are correlated site. The carbon isotope ratio methane within can be accounted by combination fluid dilution ambient seawater microbial consumption kinetic effect (KIE)...
222Rn (radon) is the major radioactive gas in volcanic area. The study of radon concentration variations areas has been considered as a useful tool to investigate activity one Tatun Volcano Group, where close Taipei basin and exhibits active fumaroles hot springs, was chosen for first time systematical Hsiao-You-Keng hydrothermal area northern Taiwan. In addition soil CO2 flux compositions, concentrations were measured situ by an analogous sensor. sensor developed separate electronics from...
This study focused on the chemistry of sedimentary pore fluids to clarify hydrothermal fluid migrating within sediments at Geolin Mounds (GLM) and Mienhua Volcano (MHV) fields, southernmost Okinawa Trough, where are characterized by covering thick sediment. The significant downward decrease in Mg2+ (low 23.3 mmol L−1) concurrent increase Li+ (up 2,269 μmol implied a substantial influence fluid, which might be associated with high-temperature (>350 °C) rock/sediment-fluid interaction. best...
Spatial variations in the atmospheric helium isotopic composition (RA = 3He/4Heair 1.39 × 10−6) might be induced by localized and/or regional inputs of 3He 4He into air. It has been suggested that from hydrocarbon exploitation may generate latitudinal 3He/4He. In order to test possibility such global variations, we performed high precision analyses (3He/4He) sixteen air samples collected 500 cc metal bottles around world (79°N–75°S) between 2013 and 2015. most cases, 3He/4He these are...
The composition of atmospheric helium is generally considered to be constant ( 3 He/ 4 He = 1.39 × 10 − 6 ) on a large spatial scale. However, local variations may arise in tectonically active areas due focussed degassing one its two isotopes, for example mantle-derived or crustal-derived He. If detected, such have the potential trace open conduit magmatic bodies and/or diffusive emissions from volcanic crustal sources. Here, we test possibility detecting Afar region north-eastern Ethiopia,...
Abstract The abundance and isotopic compositions of volatile elements trapped in fluid inclusions submarine hydrothermal mineral deposits Western Pacific subduction zones (Okinawa Trough, Izu‐Bonin arc, Mariana Lau Basin) Kuroko ores northeastern Japan are presented. helium corrected for air contribution the Okinawa troughs, ranging 4.49–7.68 Ra lower than those Basin, 7.62–8.91 Ra. This characteristic might reflect differences regional tectonic setting. troughs related to back‐arc spreading...
Abstract CO 2 released from subduction zones plays a vital role in the tectonic carbon cycle. However, contribution of submarine backarc components to emissions remains poorly understood compared subaerial arc volcanos. This study utilized combination geochemical and hydrodynamic approaches investigate sources flux dissolved inorganic (DIC) deep basin southwestern Okinawa Trough. Most deep‐water (depth ≥1,000 m) samples, even those retrieved sites distant active venting, exhibited mild...
Abstract A small hydrovolcanic eruption occurred on Mt. Hakone in central Japan 29 June 2015, ejecting amounts of volcanic ash and gas. We have conducted continuous surveys He isotopes the Owakudani geothermal area close to Komagatake, cone Hakone. Long‐term (decadal‐scale) data from Black‐egg site show generally constant 3 He/ 4 ratios with 6.37 ± 0.06 R a , where is atmospheric ratio 1.382 × 10 ‐6 after air correction. Short‐term (monthly) two fumarole sites indicate rapid increase May...