Arrival-angle anomalies across the USArray Transportable Array
Por:
Foster A., Ekstrom, G, Hjorleifsdottir, V
Publicada:
15 sep 2014
Resumen:
We construct composite maps of surface-wave arrival-angle anomalies
using clustered earthquakes and an array method for measuring wave-front
geometry. This results in observations of arrival angles covering the
entire footprint of the USArray Transportable Array during 2006-2010.
Bands of arrival-angle deviations in the propagation direction indicate
the presence of heterogeneous velocity structure both inside and outside
of the array. We compare the observed patterns to arrival angles
predicted using two global tomographic models, the mantle model S362ANI
and the surface-wave-dispersion model GDM52. We use both
ray-theory-based prediction methods and measurements on synthetic data
calculated using a spectral-element method. Both models and all
prediction methods produce similar mean arrival angles and
long-wavelength patterns of anomalies which are similar to the
observations. Predicted short-wavelength features generally do not agree
with the observations. The spectral-element method produces some
complexity that is not obtained using the ray-theory-based methods; this
predicted complexity is similar in character to the observed patterns,
but does not match them. (C) 2014 Elsevier B.V. All rights reserved.
Filiaciones:
Foster A.:
Department of Earth and Environmental Sciences, Columbia University, 61 Route 9W, Palisades, NY 10964, United States
Hjorleifsdottir, V:
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico
All Open Access; Green
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