 |
| Titel |
Two-station Rayleigh and Love surface wave phase velocities between stations in Europe |
| VerfasserIn |
Ö. Çakir, A. Erduran, E. Kırkaya, Y. A. Kutlu, M. Erduran |
| Konferenz |
EGU General Assembly 2012
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250059497
|
|
|
|
|
|
| Zusammenfassung |
| We study the Rayleigh and Love surface wave fundamental mode propagation beneath the
continental Europe and examine inter-station phase velocities employing a two-station
method for which the source code developed by Herrmann (1987) is utilized. In the
two-station method, the near-station waveform is deconvolved from the far-station waveform
removing the propagation effects between the source and the near-station. This method
requires that the near and far stations are aligned with the epicentre on a common great
circle path for which we impose the condition that the azimuthal difference of the
earthquake to the two stations and the azimuthal difference between the earthquake to the
near-station and the near-station to the far-station are smaller than 5o. From the IRIS and
ORFEUS databases, we visually select 3002 teleseismic, moderate-to-large magnitude
(i.e.Mw -¥ 5.7) events recorded by 255 broadband European stations with high
signal-to-noise ratio within the years 1990-2011. Corrected for the instrument response,
suitable seismogram pairs are analyzed with the two-station method yielding a
collection of phase velocity curves in various periods ranges (mainly in the range
25-185 s). Diffraction from lateral heterogeneities, multipathing, interference of
Rayleigh and Love waves can alter the dispersion measurements. In order to secure
the quality of measurements we select only smooth portions of the phase velocity
curves, remove outliers and average over many measurements. We finally discard
these average phase velocity curves suspected of suffering from phase wrapping
errors by comparing them with a reference Earth model (i.e. IASP91 by Kennett and
Engdahl 1991). The outlined analysis procedure yields 5109 Rayleigh and 4146 Love
individual phase velocity curves. The azimuthal coverage of the respective two-station
paths is proper to analyze the observed dispersion curves in terms of both azimuthal
and radial anisotropy beneath the study region. This work is supported by Turkish
Scientific and Technical Research Council (TUBITAK) (project number 109Y345). |
|
|
|
|
|
|