地殻変動と地震予知-下向きの研究から上向きの研究へ-

Abstract

北丹後地震で大被害を受けた丹後地方には椋平虹による地震予知に期待を寄せた人々もあった。筆者が地震予知の研究に携わるようになったのもその影響を受けたのかも知れない。Sassa&Nishimura(1951)の有名な研究を受けて, 傾斜計・ひずみ計による前兆的な地殻変動の検出をめざした。最近の宇宙技術による地殻変動の観測に加えて海底や深いボア・ホールでの観測により, 地震予知の研究は着実に進められていくと期待できる。

Mukuhira Niji(rainbow) was very famous as a special forerunner of big earthquakes found by an amateur, Mr. Mukuhira in the Tango area, attacked by the Kita-tango earthquake(M7.3) in 1927 and suffered by a great damage. The anomalous tilt observed by Sassa and Nishimura at Ikuno Mine before the Tottori earthquake in 1943 encouraged scientific research of earthquake prediction by observing crustal movements.Recent researches suggest that it seems difficult to catch such anomalous crustal movement forerunning big earthquakes. Combination of observations with space techniques such as GPS and SAR and conventional techniques such as strainmeters, tiltmeters and precise distance meters at more deeper part underground and ocean bottom will open a way to long-term prediction of earthquakes.