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Absorption of P‐ and S‐waves above subduction zones
Author(s) -
Temme YorckFabian,
Weber Michael,
Wicks Charles W.
Publication year - 2000
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl011004
Subject(s) - subduction , geology , seismology , range (aeronautics) , absorption (acoustics) , physics , tectonics , optics , materials science , composite material
We investigate local variations of absorption above the subduction zones of the northwest Pacific. Teleseismic broad‐band (BB) recordings at German arrays from 59 earthquakes in this area allow the determination of the quality factor Q P and Q S . The method to determine Q is the phase pair method. Here, for the first time, P‐wave BB‐recordings at dense arrays are used, extending the frequency range studied and increasing the reliability of the Q P determination for the northwest Pacific. 1‐D Earth models have typical Q P values of 200 to 800 ( Q S : 100 to 400) in the upper 200 km. Q P under the Kuriles, the Kurile Basin and Japan is about 100, i.e. significantly lower than average. Q S under Japan is also only about 1/3 of the value of 1‐D models. No frequency dependence of Q P and Q S could be detected for the broad frequency range studied [0.05 to 1 Hz].