Open AccessCaustics Produced by Waves Through the Earth's Core *
Author(s) -
Gutenberg B.
Publication year - 1958
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.1958.tb00057.x
Subject(s) - caustic (mathematics) , inner core , diffraction , core (optical fiber) , geology , outer core , phase (matter) , range (aeronautics) , physics , geophysics , optics , materials science , composite material , quantum mechanics , mathematical physics
Summary Caustics produced by SKP, PKS, PKP and other phases through the Earth's core are investigated. No impulses from diffracted waves with periods of two seconds or more have been found beyond five degrees from caustics. Short waves preceding the main PKIKP ‐phase at distances between 125° and 140° probably have their deepest point in or near a transition zone between the liquid outer and the probably solid inner core and it is unlikely that they are related to the caustic of PKP near 145° although their travel‐time curves end near this caustic. The observed range of long‐period waves diffracted beyond the caustics of several phases is smaller than the maximum range calculated by Jeffreys.