| タイトル | HF Doppler observations of acoustic waves excited by the earthquake |
| 著者（英） | Sato, Y.; Tanaka, T.; Ichinose, T.; Ogawa, T.; Shibata, T.; Takagi, K.; Okuzawa, T.; Nagasawa, C. |
| 著者所属（英） | Doshisha Univ. |
| 発行日 | 1985-12-01 |
| 言語 | eng |
| 内容記述 | Ionospheric disturbances caused by the earthquake of a relatively small and large epicentral distance have been detected by a network of HF-Doppler sounders in central Japan and Kyoto station, respectively. The HF-Doppler data of a small epicentral distance, together with the seismic data, have been used to formulate a mechanism whereby ionospheric disturbances are produced by the Urakawa-Oki earthquake in Japan. Comparison of the dynamic spectra of these data has revealed experimentally that the atmosphere acts as a low-pass filter for upward-propagating acoustic waves. By surveying the earthquakes for which the magnitude M is larger than 6.0, researchers found the ionospheric effect in 16 cases of 82 seismic events. As almost all these effects have occurred in the daytime, it is considered that it may result from the filtering effect of the upward-propagating acoustic waves. |
| NASA分類 | GEOPHYSICS |
| レポートNO | 86N27784 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/388382 |
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