爆破地震動観測による本州中央部を南北に横断する測線上の地殼構造
第1部 紫雲寺・安中・河津爆破地震動の観測
1964 年 17 巻 4 号 p. 187-200
詳細
1964 年 17 巻 4 号 p. 187-200
Since November 1961, about one ton explosives were detonated three times by the Research Group for Explosion Seismology for the purpose of elucidating the crustal structure along the longitudinal line of 139°E, the boundary geologically dividing Honshu into northeastern and southwestern blocks.
Blasts were carried out at Siunzi town, Annaka city and Kawazu town, which are located in the north, middle and south part of the boundary respectively. Seismic waves from the three blasts were observed successfully by our Group at temporary stations, 52 in total, spread along the boundary up to distance of about 300km.
Observed data and travel time graphs of each observation are given in this paper. At the time of the Annaka explosion, seismic waves from a natural earthquake occurred near Miyake-jima about one minute before the scheduled shot time were observed at our temporary stations. These data as well as those obtained at J. M. A. routine stations are also given.
