Automatic determination of depth phases and earthquake focal depth using Cepstral Stacking Method (CSM) and Standing Order of Data (SOD)

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Automatic determination of depth phases and
earthquake focal depth using Cepstral Stacking
Method (CSM) and Standing Order of Data (SOD)

• Recep Cakir
• recep.cakir_at_dnr.wa.gov
• Lingsen Meng
• lsmeng_at_caltech.edu
• Michel Foundotos
• foundoto_at_geoazur.unice.fr
• Chin-Wu Chen
• cwchen_at_ciw.edu

EarthScope USArray Data Processing and Analysis
Short Course Student Project August 29,
2010 Northwestern University, Evanston-Chicago
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Objectives

• Create an automatic process to detect depth
  phases (pP and /or sP) and determine focal depth
• Report focal depth additional to ones from
• USGS/IRIS/CMT/regional networks
• Report depth phases additional to ISC and
  regional network bulletins

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Focal depth calculation
Depths from pP and sP delay times
h
Alexander and Cakir, 2010
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Cepstral Method
Alexander and Cakir, 2010
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Alexander and Cakir, 2010
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Cepstral Stacking Method (CSM)
Alexander and Cakir, 2010
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CSM data processing workflow (in SAC)
Alexander and Cakir, 2010
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AUTOMATIC PROCESSING
Master script (Matlab) SOD Download earthquake
catalog and waveform data

• INITIALIZE PARAMETERS
• Sub-Window Length (sec)
• Percentage Overlap ()
• Stacking (product, sum, both)
• Multiple Station Stacking (Y/N)
• Display (all/final sub-stack plots)
• Automatic Depth Estimation (Y/N)

PROCESS Station k (k1,M) STACK STATION
CEPSTRA FINAL DEPTH ESTIMATE
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SOD recipe
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Matlab master script
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Conclusion

• Rapid, automatic detection of depth phases and
  focal depth
• Integrate programming of SOD, Matlab, and SAC

Discussion

• Estimation of focal mechanism
• Comparison with theoretical travel time
  prediction
• Quality control system
• Array processing enhances precision

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References

• Alexander, S.S. and Cakir, R. (2010) Further
  Development of the Cepstral Stacking Method (CSM)
  for Accurate Determinations of Focal Depths for
  Earthquakes and Explosions., Seismo. Res. Let.,
  81, 2, p356, 2010.
• SOD manuals - http//www.seis.sc.edu/sod/
• Matlab manuals - http//www.mathworks.com/
• SAC manuals - http//www.iris.edu/software/sac/man
  ual.html