Open AccessUppermost inner core attenuation from PKP data observed at some South American seismological stations
Author(s) -
Ivan Marian,
Marza Vasile,
De Farias Caixeta Daniel,
De Melo Arraes Tassia
Publication year - 2006
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2006.02847.x
Subject(s) - attenuation , geology , amplitude , seismology , geodesy , gaussian , inner core , core (optical fiber) , pacific ocean , oceanography , physics , optics , quantum mechanics
SUMMARYQ Pfactor at the top of the inner core (IC) is derived using the amplitude spectral ratio (PKPbc versus PKPdf) method applied to the waveforms of suitable, strong (magnitude >6.0) intermediate depth and deep ( h > 150 km) earthquakes recorded at some selected South American stations. In most cases, the sampled volume of the IC is centred beneath the Pacific Ocean, but some Q P values correspond to volumes under South Africa and under Northern Atlantic. The obtained value of Q P is 323 ± 16 (at 95 per cent confidence level), close to a normal (Gaussian) distribution. The maximum depth of penetration of the PKPdf phase into the IC is roughly 333 km, suggesting a possible increase of Q P with depth, although the large scatter in data prevents a definite conclusion. As regards the geographical patterns no variation was observed.