jgg     2008 28 (4):  44-53    ISSN: 0412-1961  CN: 21-1139/TG PROGRESS AND CURRENT SITUATION OF RESEARCHON THEORY AND OBSERVATION OF GRAVITY CHANGECAUSED BY SEISMICITY AND VOLCANISM Sun Wenke Earthquake Research Institute, the University of Tokyo, Tokyo 113-0032 Japan Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null