Faculty Staff
Measurement and Evaluation
Sumino, Hirochika
Professor
Ph. D.
Ph. D.
Isotope Geochemistry and Cosmochemistry, Mass Spectrometry, Volcanology, Geochronology
Isotope Geochemistry and Cosmochemistry Laboratory
sumino [at] igcl.c.u-tokyo.ac.jp
TEL: +81-3-5454-6741 FAX: +81-3-5454-6741
Educational background
March 1996 Bachelor of Science in Chemistry, The University of Tokyo
March 1998 Master of Science in Chemistry, The University of Tokyo
April 2001 Doctor of Science in Chemistry, The University of Tokyo
Profile
Through my whole academic career I have been investigating the origins and behaviours of volatiles in the terrestrial mantle by using highly-sensitive, precise noble gas mass spectrometry. I have developed the original ion source and detector for noble gas mass spectrometers to achieve high sensitivity comparable to or even better than commercially-available brand-new mass spectrometers. Particularly, technique of isotope ratio analysis for all of the five noble gas elements (helium, neon, argon, krypton, and xenon) for a single sample of various types (gases, fluids, rocks, and minerals) using several extraction methods (in vacuo crushing, heating, and laser microprobe) is unique not only in Japan but also in the world. By using the technique, I have revealed the deep-mantle origin of diamonds and kimberlites, traces of subduction-related metasomatism in subcontinental lithospheric mantle, and magmatic volatile distributions in hydrothermal systems around active volcanoes.
While visiting the University of Manchester, UK in 2006, I learned a technique for trace halogen determination combining neutron irradiation and noble gas mass spectrometry. I applied the method to decipher the origin of water subducted into the mantle at subduction zones. I have revealed that water derived from sedimentary pore fluids are conveyed into the mantle by the subducting oceanic lithosphere and modify the halogen and noble gas compositions of the mantle wedge down to a 100 km depth.
Recently I have been working on a capability of helium isotope ratios of volcanic and hot-spring gases for volcano monitoring. I am developing a portable mass spectrometer having high sensitivity and mass resolution capable of helium isotope analysis in the field.