A5060938692- Geological and Geochemical Analysis
- earthquake and tectonic studies
- Seismology and Earthquake Studies
- Geology and Paleoclimatology Research
- Geochemistry and Geologic Mapping
- High-pressure geophysics and materials
- Geological and Geophysical Studies
- Radioactive contamination and transfer
- Landslides and related hazards
- Earthquake Detection and Analysis
- Earthquake and Disaster Impact Studies
- Mineralogy and Gemology Studies
- Geological formations and processes
- Geological Modeling and Analysis
- Remote Sensing and Land Use
- Methane Hydrates and Related Phenomena
- Seismic Waves and Analysis
- Hydrocarbon exploration and reservoir analysis
- Traditional Chinese Medicine Studies
- Marine and Coastal Research
- Remote-Sensing Image Classification
- CO2 Sequestration and Geologic Interactions
- Visual perception and processing mechanisms
- Planetary Science and Exploration
- Wind and Air Flow Studies
Tokoha Gakuen University
2013-2024
Kagoshima University
2024
Fuji Tokoha University
2009-2017
The University of Tokyo
2001-2008
Tohoku University
2006-2007
Earthquake Engineering Research Institute
2001
A plinian-style eruption with a radially spreading umbrella cloud occurred on February 13, 2014, at Kelud volcano, Indonesia. We present the sequence of this plinian event based geological survey products and analysis satellite images. The eruptive deposits were divided into four major depositional units (Units A, B, C, D) used to determine events. phase was preceded by partial destruction existing lava dome generation high-energy pyroclastic density currents (PDCs) mainly toward NE that...
The phreatic eruption at Ontake volcano on 27 September 2014, which caused the worst volcanic disaster in past half-century Japan, was reconstructed based observations of proximal pyroclastic density current (PDC) and fallout deposits. Witness were also used to clarify process. deposits are divided into three major depositional units (Units A, B, C) characterized by massive, extremely poorly sorted, multimodal grain-size distribution with 30–50 wt% fine ash (silt–clay component). condition...
A phreatic eruption at Mount Ontake (3067 m) on September 27, 2014, led to 64 casualties, including missing people. In this paper, we clarify the sequence of 2014 from recorded images (photographs and videos obtained by climbers) interviews with mountain guides workers in huts. The onset was sudden, without any clear precursory surface phenomena (such as ground rumbling or strong smell sulfide). Our data indicate that can be divided into three phases. Phase 1: started dry pyroclastic density...
After a precursory phreatic stage (2008 to 2010), the 2011 Shinmoe-dake eruption entered phreatomagmatic on January 19, sub-Plinian and lava accumulation at end of January, vulcanian in February–April, second June–August. Component ratio, bulk composition, particle size samples helped us define eruptive stages. The juvenile particles were first found 19 sample as pumice (8 vol%) consistently present scoria thereafter (generally ~50 vol%, decreasing weaker events). has water-quench texture....
The 2000 eruption of Miyakejima volcano started with a submarine basaltic andesite on the morning June 27, which occurred following earthquake swarms during previous night. main phase summit began, being associated by sudden subsidence area July 8. Continuous collapsing that had continued until midAugust, resulted in formation caldera volume about 0.6 km3. Phreatic (or phreatomagmatic) eruptions took places growth caldera, although total eruptives was 11 million m3. is smaller one magnitude...
Eruption scenarios were prepared as possible sequences in event trees for six active volcanoes Indonesia, that are located near populated areas or have erupted recent years (Galunggung, Guntur, Kelud, Merapi, Semeru, and Sinabung). The here show of eruption phenomena without probabilities on branches cover experienced historical pre-historical eruptions based archives field research results. Changing magma discharge rates during considered the tree Merapi. This conceptual can also be used a...
Kelud Volcano is among the most active volcanoes in Indonesia, with repeated explosive eruptions throughout its history. Here, we reconstructed relationship between repose period and cumulative volume of erupted material over past 100 years estimated long-term magma discharge rate future eruptive potential hazards. Tephra data eruption sequences described historical documents were used to estimate mass rate. The volumes 1901, 1919, 1951, 1966, 1990, 2014 as 51–296 × 10 6 m 3 . rates be on...
Faunal compositions and 14C ages of emerged sessile assemblages at four sites in the southern part Izu Peninsula, central Japan, indicate that co-seismic uplift occurred 1256–950 BC, AD 1000–1270, 1430–1660, 1506–1815. The data suggest stress field Peninsula changed to its current north–south compression ca. 3100 BP, recurrence intervals for uplift-inducing earthquakes have become shorter during last 1000 years. main faults responsible this seismicity appear be located offshore from south...
Abstract The variation of sulphur isotopic composition during the 2000 eruption Miyakejima Volcano was examined in order to monitor temporal change volcanic activity. δ 34 S values water‐soluble sulphate leached from ash effused intermittent eruptions July September 2005 range +5 +11‰ with a fluctuation ca 3‰ within single eruption. value sulphuric acid mist collected ‘Cu‐metal trap’ placed on flank volcano December January 2001 is +6.2‰. These compositions sulphate, which were isotopically...
Abstract The color of pyroclasts is fundamental because it affected by the processes and properties magma that derive diversity in eruption style, as well particle morphology, chemistry, petrological characteristics. Currently, to componentry or ratio each component (CR) monitor ongoing eruptions. However, description derivation have not yet been fully established a robust quantitative standard. CR, other analyses, too laborious time-consuming introduce sustainable monitoring method. In this...
Abstract The color of pyroclasts is fundamental, because it reflects various magma properties and eruption processes, including particle morphology, chemistry, petrological characteristics. However, deriving the componentry ratio (CR) for ongoing monitoring remains challenging due to lack a robust quantitative standard. derivation CR, as well other analyses, too laborious time-consuming introduce sustainable method. To address this, we employed spectroscopic colorimetry rapidly...