On the visibility of the inner-core shear wave phase PKJKP at long periods
On the visibility of the inner-core shear wave phase PKJKP at long periods
Stacks of over 90 000 long-period seismograms recorded by the global seismic networks resolve many seismic phases but fail to detect the inner-core shear phase PKJKP. We compare these results to synthetic seismograms computed for PREM using the spectral-element method and show that expected PKJKP amplitudes are over 10 times smaller than signal-generated ‘noise’ caused by high-order P surface multiples and reverberations from upper-mantle discontinuities. Indeed, PKJKP can only be seen in synthetic seismograms when differences are taken between two sets of synthetics generated from Earth models with slightly different inner-core shear velocities. These results suggest that routine observation of PKJKP is unlikely and that reported observations, if real, must have resulted from exceptional focusing effects or inner-core attenuation much less that current models.
Core, outer core and inner core, Body waves, Computational seismology, Wave propagation
1379-1383
Shearer, Peter M.
608a51f5-3369-49f1-adb4-4e565bef4b8c
Rychert, Catherine A.
70cf1e3a-58ea-455a-918a-1d570c5e53c5
Liu, Qinya
f2821941-4c0a-49ad-8105-2761b579691f
2011
Shearer, Peter M.
608a51f5-3369-49f1-adb4-4e565bef4b8c
Rychert, Catherine A.
70cf1e3a-58ea-455a-918a-1d570c5e53c5
Liu, Qinya
f2821941-4c0a-49ad-8105-2761b579691f
Shearer, Peter M., Rychert, Catherine A. and Liu, Qinya
(2011)
On the visibility of the inner-core shear wave phase PKJKP at long periods.
Geophysical Journal International, 185 (3), .
(doi:10.1111/j.1365-246X.2011.05011.x).
Abstract
Stacks of over 90 000 long-period seismograms recorded by the global seismic networks resolve many seismic phases but fail to detect the inner-core shear phase PKJKP. We compare these results to synthetic seismograms computed for PREM using the spectral-element method and show that expected PKJKP amplitudes are over 10 times smaller than signal-generated ‘noise’ caused by high-order P surface multiples and reverberations from upper-mantle discontinuities. Indeed, PKJKP can only be seen in synthetic seismograms when differences are taken between two sets of synthetics generated from Earth models with slightly different inner-core shear velocities. These results suggest that routine observation of PKJKP is unlikely and that reported observations, if real, must have resulted from exceptional focusing effects or inner-core attenuation much less that current models.
This record has no associated files available for download.
More information
Published date: 2011
Keywords:
Core, outer core and inner core, Body waves, Computational seismology, Wave propagation
Organisations:
Geology & Geophysics
Identifiers
Local EPrints ID: 351772
URI: http://eprints.soton.ac.uk/id/eprint/351772
ISSN: 0956-540X
PURE UUID: e5dd0b6f-5ec4-4e88-8b61-95d6e26ea020
Catalogue record
Date deposited: 24 Apr 2013 10:44
Last modified: 14 Mar 2024 13:43
Export record
Altmetrics
Contributors
Author:
Peter M. Shearer
Author:
Qinya Liu
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics