Environment and Energy

Geochemistry andEnvironmental Chemistry

Sumino Laboratory

Material
Environment and Energy

Isotope geochemistry and environmental chemistry of volatile elements

Information

In order to understand the formation and evolutionary process of the Earth resulting
in the present global environment, we are conducting isotope geochemistry andenvironmental chemistry research by determining the concentrations and isotope
ratios of noble gases and other highly volatile elements in meteorites, rocks andminerals derived from deep interior of the Earth. In particular, we aim to reveal theorigin and cycling of water, which makes the Earth a habitable planet.
Noble gas isotopes (He, Ne, Ar, Kr, and Xe) are useful tracers for clarifying the origin
and history of natural samples because they have diverse origins. However, most ofthem are extremely scarce and require special analytical techniques. We havedeveloped state of-the-art mass spectrometers for ultra-sensitive analysis of noblegas isotopes in various types of samples, solid, liquid, and gas.

Professor

Hirochika SUMINO

Chemical Biomedicine

Research Area
Isotope geochemistry and cosmochemistry, Environmental chemistry, Volatile geochemistry, Mass spectrometry

Research Associate

Yuki HIBIYA

Barrier Free

Research Area
Isotope Cosmochemistry

Contributing to disaster prevention and resource assessmentby isotope analysis

Social ScienceLaboratory forInterdiciplinary Activities

Helium isotope ratios in fumaroles and hot springs in volcanoes can be used as an indicatorof the activity of magma that causes eruption disasters. The eruption history of a volcano
can also be revealed from the He and Ar isotopes in the rocks due to the radioactive decayof other elements and cosmic ray irradiation at the Earth's surface. We are developing amethod to evaluate the degree of eruption imminence and to predict the post-eruption
processes based on the noble gas isotope ratios of various volcanic products.
Where the groundwater came from and how long it has been flowing underground areimportant in assessing the quantity and safety of groundwater as a water resource.
Analysis of tritium, a radioactive isotope of hydrogen, and 3He, an isotope of He, provides
information on the residence time of groundwater.
We contribute to disaster prevention and resource assessment using noble gas isotope
analysis and promote the understanding of global environmental change in the past,present, and future.

ColumnMy biggest motivation for research is 'to use
analytical techniques that only I can perform andmeasure things that no one else can, to discoversomething new.' In particular, I use isotope
ratios, which are the ratios of the numbers of
isotopes that make up elements, to study what isCooperative Laboratories

currently happening and what has happened in
the past on Earth and in the solar system.
I find it exciting to detect extremely small
numbers of isotopes and use this technology to
uncover previously unknown information. My
research subjects are diverse, including

Social Cooperation
Research Departments

volcanoes, groundwater, rocks and minerals,

Corporate SponsoredResearch Programssprings) from the seabed aboard Japan's proudmeteorites, and occasionally artificial objects. I
often go out into the field to collect samples.
Recently, I have had memorable experiencessuch as collecting hydrothermal water (hot1 Magnetic sector mass spectrometer fornoble gas isotope analysis

2 Primordial meteorite preserving informationon the early solar systemmanned submersible 'Shinkai 6500,' andobserving an eruption creating a new island
while collecting freshly erupted pumice on Iwo
Jima, a remote island in the Pacific Ocean.

Research Organization

https://www.igcl.c.u-tokyo.ac.jp/
sumino@igcl.c.u-tokyo.ac.jp

yuki-hibiya@igcl.c.u-tokyo.ac.jp

3 Collecting volcanic gas samples from a fumarole

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