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Travel times for Pacific earthquakes |
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| Authors: | Harold Jeffreys R A W Haddon |
| Institution: | St John's College, Cambridge CB2 1TP;Division of Seismology and Geothermal Studies, Energy, Mines and Resources, Ottawa, Canada |
| Abstract: | Summary. Pacific earthquakes studied by Gogna, also three important explosions in the Tuamotu archipelago, are rediscussed. The results are very consistent, but those from Tuamotu are later than Gogna's by about 1 s in the times of P about 60°. Both sets of data give PKP residuals about -5 s about 140° - 142°, indicating that the observations there referred to the neighbourhood of the cusp of the travel-time curve but the ISS had compared them with the DEF branch. The corresponding difference in the 1940 tables is about 2 s. Analysis at intervals of 1° indicated that the cusp of PKP is about 141° instead of 143° as in the 1940 tables and the difference between it and the DEF branch at these distances is about - 5 s. Travel times of S under the Pacific were found but need more data, especially at distances under 10°. Times of PcP reported by Kogan and Carder were compared with those calculated from P in Gogan's explosions, and indicated a radius of the core of 3479.8 ± 1.8 km. |
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