Geodesy and Physics of Crustal Movements
The purpose of modern geodesy is to know the shape of the earth, its gravitational field, parameters of the earth’s rotation and their temporal changes. These themes have close relationships with other disciplines of earth and planetary sciences. We observe the whole earth by utilizing space geodetic techniques (GPS, InSAR, and satellite gravity measurement) and precise geodetic apparatus (altimeters, superconducting gravimeters, absolute gravimeters, and laser extensometers). Our research areas range from observation and data analysis to numerical simulations.
Seismology and Physics of the Earth's Interior
Why and how do large earthquakes occur? Can we forecast when and where the next earthquake will occur? What is the structure of the Earth's interior?
Our research aims to answer such questions with theory, observation, data analysis, numerical simulations and laboratory experiments. Seismology and Physics of the Earth’s interior are evolving disciplines with many unsolved problems. We welcome all those that want to challenge these exciting aspects of seismology.
Crustal Geophysics and Active Tectonics
Studies of strong motion aim to understand the mechanisms of occurrence and propagation of earthquakes. Our research subjects are the analysis and modeling of seismic wave generation during propagation of fault rupture, seismic wave propagation in the Earth's crust and sedimentary plains, and seismic wave amplification according to basement structures of sedimentary basins. The results of this research are synthesized to find a reasonable method of forecasting strong motions.
The targets of active tectonics are Quaternary and ongoing crustal deformation and earthquakes, with their resultant landforms and geologic structures. We especially focus on inland active faults responsible for epicentral earthquakes and plate boundary faults which cause massive earthquakes around ocean trenches. The research aims are to elucidate the faulting histories and to make long-term forecasts.
Physical Volcanology aims to clarify the whole process of eruption, including magma formation and upwell, through geophysical methods based on seismology, geodesy, geothermal science and electromagnetics. Kyoto University internationally leads this research field. Our study themes are as follows. (1) What occurs before volcanic eruption? (2) What occurs during volcanic eruption? (3) How diverse is the volcanic process and what controls it?
Experimental and theoretical research is performed to understand various phenomena caused by the earth's internal heat source. We have the Institute for Geothermal Sciences and the Aso Volcanological Laboratory in central Kyushu Island, where volcanic and geothermal activities are prominent. The Kyoto branch office is also used. Analytical instruments and observatories for seismic waves, crustal deformation, electromagnetism and geothermal heat facilitate the research activities.
We aim to understand the present state and history of the environment at the earth’s surface (mainly on land), which is the sphere of human activity. Japanese islands are subject to some of the most active tectonic deformation on earth, causing landslide disasters frequently occur at steep slopes located everywhere from high mountains to plains. Our target is the process of such ground surface deformations.
We are researching the processes of hydrological circulation around the ground surface, mass transport, and steep slope collapse by various methods of physics, chemistry, geomorphology, and hydrology. Our laboratories for education and research are located in Beppu (Institute for Geothermal Sciences) and Uji (Disaster Prevention Research Institute).
By investigating the physical mechanisms of oceanic phenomena through observation, theory and numerical modeling, we intend to understand the roles of oceans in the formation and change of the Earth's climate. The unknown aspects of oceanic phenomena can be revealed by means of up-to-date techniques such as analysis of data acquired by satellites, ships, and buoys; analysis of turbulent flow through precise numerical modeling; and assimilation experiments.
Meteorology, Climate Physics, and Atmospheric Physics
The target of our observational, analytical, experimental, and theoretical research is the atmosphere which is 100 km in thickness from the ground surface. There are four major fields. (1) Atmospheric physics and chemistry intend to understand the thermal structure, circulation and chemical composition of the atmosphere. (2) The mechanisms of the formation and changes of climate are studied in climate system science. (3) Atmospheric disaster and environmental sciences aim to understand and predict atmospheric disasters and environmental changes. (4) Geophysical fluid dynamics deals with the motion of rotating or stratified fluid.
Solar-Planetary Physics and Geomagnetism
We study various phenomena in the wide area from the Earth’s core to distant planets, including the ocean, atmosphere, ionosphere, magnetosphere and solar wind, based on electromagnetism and plasma physics. For example, we study the shock waves in solar wind, magnetic storms and substorms, plasmas and waves in the magnetosphere and the ionosphere, geomagnetic secular variation etc. We conduct observations both on the ground and on the deep sea floor, and we do remote sensing with radar and GPS, plasma particle and airglow measurements using satellites, computer simulation and data analysis.
Electromagnetism of the Earth's Interior
We are addressing various problems in Solid Earth Sciences based on knowledge of modern electromagnetism. Recent research topics are spatial distribution and temporal variations of the Earth's magnetic field and natural electric potential, and electrical conductivity structure of the Earth’s crust and mantle. Field observation, not only on land but also at the seafloor or even in the air, is crucial to delineate seismic and/or volcanic activities around faults/volcanoes. We also place emphasis on numerical modeling/simulation in order to interpret the valuable field results.
Geotectonics deals with solid earth phenomena on a global scale and the timescale of the earth’s history. Recent interests are radioactive dating, isotope analysis, and deformation mechanisms of fault rocks. The research methods are mainly observations and measurements during field work, indoor analyses and experiments using rock samples, employing modeling and theories to support them. Our research and education are at the forefront of the field of geotectonics. We aim to substantially clarify multiple aspects of geotectonic phenomena.
Material Science of the Earth
The petrology group focuses on metamorphic and igneous rocks, including mantle peridotite. By chemically analyzing rock-forming minerals and fluid inclusions, and through field work and theoretical studies, we aim to understand the correlation between temperature, pressure, time, deformation and fluid activity in the rocks formed at convergent plate boundaries in order to take on the challenge of understanding the magnificent dynamics of the solid Earth.
The mineralogy group focuses on the properties and origins of rock-forming minerals as primary components of the earth and other planets. We aim to understand mineral forming processes and thermal/stress histories after their formation, based on observations, analysis, experimental and theoretical studies of crystal structure, chemical composition and microstructure of minerals.
Historical Geoscience of the Biosphere
Historical Geoscience of the Biosphere aims to understand the evolutionary history of the earth’s biosphere, which includes organisms and their habitat---the shallow part and the surface of the planet. For this purpose, sedimentary rocks, which cover 90% of the earth’s surface, are important, because they yield fossils and are by themselves archives of historical records. This group deals with strata and fossils to understand specifically the evolutionary history of organisms (paleontology), deformations of the lithosphere (structural geology) and environmental changes (paleoenvironmentology), by means of geological field work, sample analysis, theoretical and experimental approaches.
Geochemistry is one of the key research fields to derive the direct evidence of the growth history of the Earth and the Solar System. We are trying to understand the evolutionary sequence of the solar system, meteorites, planetary core, and the origin and evolution of life through elemental and isotopic data. To achieve this, we are developing state-of-the-art techniques for elemental analysis using the laser plasma mass. One newly developed analytical technique has blossomed to become a method of choice for many geochemists, chemists and biochemists because it is much more versatile, user friendly and efficient method for the elemental analysis of industrial and biochemical samples.