Seismic experiments on the North German explosions, 1946 to 1947

摘要: Seismic waves produced by explosions near Soltau were observed at distances up to 50 km., and others from the Heligoland explosion 1000 km. Special time signals a high recording speed enabled instant of sharp onset be determined 0·1 sec. Short-range seismic data used eliminate some effect rocks surface. The average velocity first arrivals was 4·4 km./sec. between 4 24 shot point, 5·95 120 8·18 beyond Significant local variations found shorter distances. Alternative hypotheses covering distribution in upper layers gave estimates 27·4 29·6 for depth ultrabasic layer. Later proved difficult identify, statistical method estimate significance travel-time curves drawn through selected groups onsets. This test showed that P * not significantly recorded, but number onsets 7 or 8 after n probably represented wave travelling most its path layer reflected critical angle failed decide whether close expected times g should treated as one more phases. Confused motion persisted during period when transverse expected, but, with possible exception S , there no significant concentration observations about lines representing recognized thermal energy 1·3 x 10 20 ergs, order 17 ergs. efficiency therefore comparable surface explosion, measurements crater confirmed rock which covered charge could have had much on momentum entering ground.