Surface Wave Propagation through the Bohemian Massif Preliminary Results from the PASSEQ Experiment Jiri Malek Petr Kolinsky Oldrich Novotny Renata Gazdova and PASSEQ working group Institute of Rock Structure and Mechanics Academy of Sciences of the Czech Republic ESC 2008 September 2008 Hersonissos, Crete, Greece
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Jiri Malek Petr Kolinsky Oldrich Novotny Renata Gazdova and PASSEQ working group
Surface Wave Propagation through the Bohemian Massif Preliminary Results from the PASSEQ Experiment. Jiri Malek Petr Kolinsky Oldrich Novotny Renata Gazdova and PASSEQ working group Institute of Rock Structure and Mechanics Academy of Sciences of the Czech Republic. ESC 200 8 - PowerPoint PPT Presentation
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Surface Wave Propagation through the Bohemian Massif Preliminary Results from the PASSEQ Experiment
Jiri MalekPetr KolinskyOldrich NovotnyRenata Gazdovaand PASSEQ working group
Institute of Rock Structure and MechanicsAcademy of Sciences of the Czech Republic
ESC 2008September 2008
Hersonissos, Crete, Greece
Malek, Kolinsky, Novotny and Gazdova: Surface waves 2
Contents
PASSEQ experiment
Surface wave analysis
Mean S-wave model of the Bohemian Massif
Conclusions
Malek, Kolinsky, Novotny and Gazdova: Surface waves 3
Contents
PASSEQ experiment
Surface wave analysis
Mean S-wave model of Bohemian Massif
Conclusions
PASSEQ - Passive Seismic Experiment in the Trans-European Suture Zone
Experimental part:May 2006 - June 2008
147 SP and 49 BB stations inPolandGermanyCzech Republicand Lithuania
Surface wave analysisPreliminary results from the Bohemian MassifData from PASSEQ and from the Czech Regional Seismic network
Malek, Kolinsky, Novotny and Gazdova: Surface waves 4
Selected earthquakes for surface wave studies
56 earthquakes MS>5.5 with a good azimuthal coverage
Contents
PASSEQ experiment
Surface wave analysis
Mean S-wave model of Bohemian Massif
Conclusions
Malek, Kolinsky, Novotny and Gazdova: Surface waves 5
Azimuthal coverage at station Pruhonice (PRU)
Contents
PASSEQ experiment
Surface wave analysis
Mean S-wave model of Bohemian Massif
Conclusions
Malek, Kolinsky, Novotny and Gazdova: Surface waves 6
Continental pathKurile IslandsM 8.1 and M 8.38.600 km
Mainly oceanic pathScotia SeaM 7.013.000 km
Different group velocity dispersion (source - station)
Contents
PASSEQ experiment
Surface wave analysis
Mean S-wave model of Bohemian Massif
Conclusions
Malek, Kolinsky, Novotny and Gazdova: Surface waves 7
Different group velocity dispersions (source - station)Continental pathKurile IslandsM 8.1 and M 8.38.600 km
Mainly oceanic pathScotia SeaM 7.013.000 km
Contents
PASSEQ experiment
Surface wave analysis
Mean S-wave model of Bohemian Massif
Conclusions
Malek, Kolinsky, Novotny and Gazdova: Surface waves 8
Same phase velocity dispersions (station - station)
Kurile IslandsM 8.1 and M 8.3
Scotia SeaM 7.0
Contents
PASSEQ experiment
Surface wave analysis
Mean S-wave model of Bohemian Massif
Conclusions
Malek, Kolinsky, Novotny and Gazdova: Surface waves 9
Time-frequency transformation
• multiple filtering with Gaussian filters• constant relative resolution filtering• instantaneous period estimation
0.0 0.1 0.2 0.3 0.4 0.5 0.6frequency (Hz)
ampl
itude
pow er spectrumG aussian filte rsfilte red power spectra
Malek, Kolinsky, Novotny and Gazdova: Surface waves 21
red line - present study, violet line - vSV (model STW105)
Kustowski B., Ekström G., and A. M. Dziewoński (2008), Anisotropic shear-wave velocity structure of the Earth's mantle: A global model , J. Geophys. Res., 113.
Contents
PASSEQ experiment
Surface wave analysis
Mean S-wave model of Bohemian Massif
Conclusions2.0 2.5 3.0 3.5 4.0 4.5 5.0
shear w ave veloc ity [km /s]
200
150
100
50
0
dept
h [k
m]
Malek, Kolinsky, Novotny and Gazdova: Surface waves 22
Conclusions- PASSEQ data were used for determination of an S-wave velocity model of the Bohemian Massif down to 200 km from surface waves dispersion.
- Rayleigh wave phase velocity dispersion curves between couples of stations were studied.
- Low velocity channel (astenosphere) was found in the depths of 50 – 145 km.
- Astenosphere is more pronounced than in the average world model STW 105.
Many thanks to Jan Zednik for data from the Czech Regional Seismic Network