Open AccessTravel times for Pacific earthquakes
Author(s) -
Jeffreys Harold,
Haddon R. A. W.
Publication year - 1983
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1983.tb03783.x
Subject(s) - archipelago , cusp (singularity) , geology , seismology , pacific ocean , geodesy , travel time , geography , mathematics , geometry , oceanography , engineering , transport engineering
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.