Abstract
The frequency dispersion of surface waves contains information about the
seismic velocities as function of depth, allowing the estimation of
velocity models. Initially, earthquake and controlled-source records
were used to obtain dispersion curves that could subsequently be
inverted for velocity profiles. Later, also a number of methods were
developed to obtain the dispersion curves from noise recordings, e.g.,
the spatial autocorrelation method, the centerless circular array method
and seismic interferometry (as preprocessing). With the latter three
methods it is assumed that the noise comes from all directions.
Especially for small recording times, this is rarely the case. Another
method, the frequency-wavenumber technique, can handle strongly
directional fields. However, a well sampled array of stations is
required to enable unaliased transform to the wavenumber domain for a
wide band of frequencies. In this abstract, we consider the situation of
a directionally strongly biased seismic (noise) field. We work out two
new methods for estimating the backazimuth of the (noise) source(s) and
extracting the dispersion curves from the recordings. We start with a
well-sampled circular array of receivers and show that both dispersion
and source directivity can well be estimated. Subsequently, we show that
the desired parameters can still be obtained when violating the spatial
sampling criterion. Furthermore, we show that only small errors are made
when the receivers are not located on a circle. We illustrate the
methods both with synthetic data and field data from the SPITS array
(Spitsbergen, Norway).
Original language | English |
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Pages | S51A-2318 |
Publication status | Published - 1 Dec 2013 |
Event | American Geophysical Union, Fall Meeting 2013 - San Francisco, United States Duration: 9 Dec 2013 → 13 Dec 2013 |
Conference
Conference | American Geophysical Union, Fall Meeting 2013 |
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Country/Territory | United States |
City | San Francisco |
Period | 9/12/13 → 13/12/13 |
Bibliographical note
2013AGUFM.S51A2318RKeywords
- 7255 SEISMOLOGY Surface waves and free oscillations
- 7260 SEISMOLOGY Theory
- 0902 EXPLORATION GEOPHYSICS Computational methods: seismic