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Forearc decoupling of guided waves in the Chile‐Peru subduction zone
Author(s) -
Martin Sebastian,
Haberland Christian,
Rietbrock Andreas
Publication year - 2005
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 - 10.1029/2005gl024183
Subject(s) - forearc , subduction , geology , seismology , lithosphere , induced seismicity , decoupling (probability) , crust , episodic tremor and slip , oceanic crust , seismic wave , slab , geophysics , tectonics , engineering , control engineering
The structure and alterations of subducted oceanic lithosphere (e.g., thickness and seismic velocity of oceanic crust) can be obtained by analyzing guided seismic waves generated by earthquakes within the slab (Wadati‐Benioff zone). In northern Chile prominent secondary phases from intermediate‐depth seismicity, observed in the forearc region can be interpreted as guided waves. For the observation of guided waves it is usually required to have stations close to the wave guide, a fact which is not directly given for forearc stations in subduction zone environments. With the help of finite difference simulations we model the decoupling mechanism of guided waves at the contact between the descending oceanic plate and the upper plate crust where the wave guide is opened due to the equalization of seismic velocities. Provided that suited stations are available, this mechanism allows for the use of intermediate depth seismicity to study the shallow subduction zone structure (≤100 km depth).