1992 Fiscal Year Final Research Report Summary
Study of Geoid Undulation in Southwestern Japan
| Project/Area Number |
03452057
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体地球物理学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
NAKAGAWA Ichiro Kyoto University, Dept. Geophysics, Professor, 理学部, 教授 (70025279)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Kajyuro Kyoto University, Disaster Prevention Research Institute, Instructor, 防災研究所, 助手 (20135510)
TANAKA Torao Kyoto University, Disaster Prevention Research Institute, Professor, 防災研究所, 教授 (40027222)
HIGASHI Toshihiro Kyoto University, Dept. Geophysics, Instructor, 理学部, 助手 (90135517)
FUJIMORI Kunio Kyoto University, Dept. Geophysics, Instructor, 理学部, 助手 (00025470)
TAKEMOTO Shuzo Kyoto University, Dept. Geophysics, Associate Professor, 理学部, 助教授 (40027256)
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| Project Period (FY) |
1991 – 1992
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| Keywords | GEOID / ALTIMETRY DATA / GPS / GRAVITY MEASUREMENT / LEVELLING SURVEY / GEODETIC SURVEY / TIDAL OBSERVATION |
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| Research Abstract |
1. In order to determine the geoid undulation precisely in the southwestern part of Japan, data obtained from gravity measurements, levelling surveys and tidal observations as well as satellite altimetry data have been collected.
2. GPS measurements at 57 points in the southwestern part of Japan have been carried out with WM102 GPS receivers. Average repeatability of heights measured by GPS was 5.5 cm. Geoid undulation differences at these points have been determined by comparing ellipsoidal height differences measured by GPS with orthometric height ones so far obtained from levelling surveys.
3. In Tottori, Beppu, Kii and Shikoku regions, precise gravity measurements were performed with LaCoste & Romberg gravimeters.
4. Based on data mentioned above (1 - 3), a contour map of geoid undulation differences in the southwestern part of Japan was obtained. The geoid differences determined by the present study were approximately consistent with the proceeding geoids, such as the ORI-89 geoid, but systematic discrepancies of the order of a few ten centimeters were detected.
5. GPS/levelling geoid undulation differences were compared with three-dimensional seismic velocity anisotropy so far obtained from P-wave travel-time analyses.
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Research Products
(4 results)
