Development of SH Wave Generator for Seismic Sounding by High Pressure Gas Method

1990 Fiscal Year Final Research Report Summary

• Project/Area Number: 63890002
• Research Category: Grant-in-Aid for Developmental Scientific Research (B).
• Allocation Type: Single-year Grants
• Research Field: 広領域
• Research Institution: Tohoku University
• Principal Investigator: KOYAMA Junji Geophysical Institute Faculty of Science, Tohoku University, Research Scientist, 理学部, 助手 (30125546)
• Co-Investigator(Kenkyū-buntansha): MITUZUKA Takashi Tishitu Keisoku Incorporation Chief Researcher, 地震計測, 研究主任 ; ITO Akihiko Department of Education Utsunomiya University, Associate Professor, 教育学部, 助教授 (70134252)
• Project Period (FY): 1988 – 1990
• Keywords: SH wave generator / Seismic prospecting by S waves

Research Abstract

SH wave generator for seismic sounding has been originally developed in FY1988, which uses high pressure gas as energy source. The test generator was made in FY1988 and its performance tests have been done checking its safety operations and its potential power to generate seismic wave field through FY1990. The efficiencies of the test generator are summarized as follows :
1. Test generator operates safety and it can generate wave field repeatedly.
2. Test generator effectively radiates SH waves without noisy sound.
3. Test generator radiates SH waves of wide frequency band.
4. Test generator radiates SH waves with sharp onset.
5. Test generator radiates SH waves precisely repeatable with amplitude controlled by the gas pressure.
6. Test generator radiates SH waves with about twice larger amplitude than those by the wooden plate generator.
All these results lead us to judge finalizing the testing stage of the test generator and to move on to develop the generator for the practical uses.