We present a new technique for imaging spatially distributed heterogeneities
using information from combinations of source and receiver arrays.
The method is based on the single scattering assumption and is closely
related to the double beam method of Krüger et al. 1993, 1995,
1996 in that it exploits amplitude, delay time, slowness, and azimuth
information in two arrays simultaneously. A crucial step in the method
is the application of static time corrections for a chosen reference
phase (here PcP). One type of image is obtained as a spatial likelihood
distribution for prescribed source and receiver array slowness and
azimuth values and delay times with respect to a reference phase.
This allows the determination of the spatial origin of coherent phases
in the P coda. In a complementary approach, we perform a double beam
stack migration according to the theoretical slowness and azimuth
values for candidate scatterers distributed over a three-dimensional
(3-D) grid. The scattering strength is expressed as the resulting
beam power, beam amplitude, or semblance in a time window determined
from the theoretical delay time with respect to the reference phase.
While likelihood mapping provides an image reflecting the probability
of a region to explain observed kinematic phase properties by single
scattering, double beam migration provides information about the
scattering strength. The method is applied to nuclear explosion sources
in eastern Kazakhstan recorded at the Yellowknife array in northern
Canada. We identify several scattering volumes within the lower mantle
below the arctic producing individual anomalous lower mantle phases
in the P coda. These anomalies range in depth from the core-mantle
boundary (CMB) up to 500 km into the lowermost mantle and are mainly
located under the Eurasian side of the arctic. The joint interpretation
of these results with the results of previous studies suggests a
connection of these anomalies to the Cenozoic and Mesozoic subduction
of the Pacific plate and the Kula plate. The determination of the
nature of such 3-D anomalies necessitates further array studies with
better azimuthal coverage.
%0 Journal Article
%1 scherbaum_etal:1997
%A Scherbaum, Frank
%A Krüger, Frank
%A Weber, Michael
%D 1997
%J Journal of Geophysical Research
%K geophysics seismology
%N B1
%P 507--522
%R 10.1029/96JB03115
%T Double beam imaging: Mapping lower mantle heterogeneities using combinations
of source and receiver arrays
%U http://dx.doi.org/10.1029/96JB03115
%V 102
%X We present a new technique for imaging spatially distributed heterogeneities
using information from combinations of source and receiver arrays.
The method is based on the single scattering assumption and is closely
related to the double beam method of Krüger et al. 1993, 1995,
1996 in that it exploits amplitude, delay time, slowness, and azimuth
information in two arrays simultaneously. A crucial step in the method
is the application of static time corrections for a chosen reference
phase (here PcP). One type of image is obtained as a spatial likelihood
distribution for prescribed source and receiver array slowness and
azimuth values and delay times with respect to a reference phase.
This allows the determination of the spatial origin of coherent phases
in the P coda. In a complementary approach, we perform a double beam
stack migration according to the theoretical slowness and azimuth
values for candidate scatterers distributed over a three-dimensional
(3-D) grid. The scattering strength is expressed as the resulting
beam power, beam amplitude, or semblance in a time window determined
from the theoretical delay time with respect to the reference phase.
While likelihood mapping provides an image reflecting the probability
of a region to explain observed kinematic phase properties by single
scattering, double beam migration provides information about the
scattering strength. The method is applied to nuclear explosion sources
in eastern Kazakhstan recorded at the Yellowknife array in northern
Canada. We identify several scattering volumes within the lower mantle
below the arctic producing individual anomalous lower mantle phases
in the P coda. These anomalies range in depth from the core-mantle
boundary (CMB) up to 500 km into the lowermost mantle and are mainly
located under the Eurasian side of the arctic. The joint interpretation
of these results with the results of previous studies suggests a
connection of these anomalies to the Cenozoic and Mesozoic subduction
of the Pacific plate and the Kula plate. The determination of the
nature of such 3-D anomalies necessitates further array studies with
better azimuthal coverage.
@article{scherbaum_etal:1997,
abstract = {We present a new technique for imaging spatially distributed heterogeneities
using information from combinations of source and receiver arrays.
The method is based on the single scattering assumption and is closely
related to the double beam method of Kr\"{u}ger et al. [1993, 1995,
1996] in that it exploits amplitude, delay time, slowness, and azimuth
information in two arrays simultaneously. A crucial step in the method
is the application of static time corrections for a chosen reference
phase (here PcP). One type of image is obtained as a spatial likelihood
distribution for prescribed source and receiver array slowness and
azimuth values and delay times with respect to a reference phase.
This allows the determination of the spatial origin of coherent phases
in the P coda. In a complementary approach, we perform a double beam
stack migration according to the theoretical slowness and azimuth
values for candidate scatterers distributed over a three-dimensional
(3-D) grid. The scattering strength is expressed as the resulting
beam power, beam amplitude, or semblance in a time window determined
from the theoretical delay time with respect to the reference phase.
While likelihood mapping provides an image reflecting the probability
of a region to explain observed kinematic phase properties by single
scattering, double beam migration provides information about the
scattering strength. The method is applied to nuclear explosion sources
in eastern Kazakhstan recorded at the Yellowknife array in northern
Canada. We identify several scattering volumes within the lower mantle
below the arctic producing individual anomalous lower mantle phases
in the P coda. These anomalies range in depth from the core-mantle
boundary (CMB) up to 500 km into the lowermost mantle and are mainly
located under the Eurasian side of the arctic. The joint interpretation
of these results with the results of previous studies suggests a
connection of these anomalies to the Cenozoic and Mesozoic subduction
of the Pacific plate and the Kula plate. The determination of the
nature of such 3-D anomalies necessitates further array studies with
better azimuthal coverage.},
added-at = {2012-09-01T13:08:21.000+0200},
author = {Scherbaum, Frank and Kr\"{u}ger, Frank and Weber, Michael},
biburl = {https://www.bibsonomy.org/bibtex/24815d55fb3ae2bc3fbe6a2b0e3b5a4f0/nilsma},
doi = {10.1029/96JB03115},
interhash = {41da014cd47c79d85c153d85ef78d8b3},
intrahash = {4815d55fb3ae2bc3fbe6a2b0e3b5a4f0},
issn = {0148-0227},
journal = {Journal of Geophysical Research},
keywords = {geophysics seismology},
number = {B1},
pages = {507--522},
timestamp = {2021-02-09T13:27:42.000+0100},
title = {Double beam imaging: Mapping lower mantle heterogeneities using combinations
of source and receiver arrays},
url = {http://dx.doi.org/10.1029/96JB03115},
volume = 102,
year = 1997
}