Earth Planets Space, Vol. 55 (No. 5), pp. e9-e12, 2003E-LETTER
Yoshiaki Ishihara1, Shin'ya Tsukada2, Shin'ichi Sakai3, Yoshihiro Hiramatsu1, and Muneyoshi Furumoto1
1Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan
2Earthquake Prediction Information Division, Seismological and Volcanological Department of Japan Meteorological Agency, 1-3-4 Otemachi, Chiyoda, Tokyo 100-8122, Japan
3Earthquake Observation Center, Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-0032, Japan
(Received April 2, 2003; Rrevised April 29, 2003; Accepted April 30, 2003)
A high velocity passage of a meteoroid through the atmosphere generates a shock wave with a conical front. When the shock front arrives at the surface, it causes high frequency ground motions that are registered on the seismograms. We can use seismological data to determine the trajectory of the meteoroid in the atmosphere. A strong shock wave from the 1998 Miyako fireball is recorded by more than 20 stations in a dense array of seismographs installed in the northeastern region of Honshu Island, Japan. We determine the velocity and the trajectory of the fireball in the upper atmosphere using the arrival times of the shock wave at the stations.
Key words: Shockwave, fireball, trajectory, seismic array.