Affiliation: | 1. Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8567, Japan;2. Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan;3. Kanto Natural Gas Development Co., Ltd., 661 Mobara, Mobara City, Chiba 297-8550, Japan |