Open AccessAmplitude Variations with Azimuth and Distance of Short Period P Waves Recorded at some Iberian Stations
Author(s) -
Payo G.
Publication year - 1973
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.1973.tb05835.x
Subject(s) - amplitude , classification of discontinuities , azimuth , geology , slab , mantle (geology) , geodesy , lithosphere , seismology , magnitude (astronomy) , geophysics , physics , optics , tectonics , mathematics , astrophysics , mathematical analysis
Summary A large number of P amplitude measurements, obtained directly from the records of six Iberian seismological stations, has been collected to determine the relations of log ( A/T ) with azimuth and distance. A weak but significant relation has been found between the amplitudes and the structure of the upper mantle around some stations, which in the case of Málaga and Almeria has been interpreted in terms of relics of a lithospheric slab dropped into the mantle. The study of the amplitude‐distance relation obtained, as well as its comparison with other previous results confirms the existence of velocity discontinuities in the upper and lower mantle which appear to be at depths of about 840, 1000, 1260 and 2440 km. Magnitude corrections for all the stations used have also been obtained.