TY  - JOUR
AU  - Ardhuin Fabrice, Stutzmann Eleonore
PY  - 2011//
TI  - Ocean wave sources of seismic noise
T2  - J. Geophys. Res.
JO  - Journal of Geophysical Research: Oceans
SP  - C09004-
VL  - 116
IS  - C9
KW  - directional wave spectra
KW  - ocean waves
KW  - seismic noise
KW  - wave model
KW  - 4259 Ocean acoustics
KW  - 4544 Internal and inertial waves
KW  - 4560 Surface waves and tides
KW  - 7220 Oceanic crust
KW  - 7255 Surface waves and free oscillations
KW  -
N2  - Noise with periods 3 to 10 s, ubiquitous in seismic records, is expected to be mostly generated by pairs of ocean wave trains of opposing propagation directions with half the seismic frequency. Here we present the first comprehensive numerical model of microseismic generation by random ocean waves, including ocean wave reflections. Synthetic and observed seismic spectra are well correlated (r > 0.85). On the basis of the model results, noise generation events can be clustered in three broad classes: wind waves with a broad directional spectrum (class I), sea states with a significant contribution of coastal reflections (class II), and the interaction of two independent wave systems (class III). At seismic stations close to western coasts, noise generated by class II sources generally dominates, but it is intermittently outshined by the intense class III sources, limiting the reliability of seismic data as a proxy for storm climates. The modeled seismic noise critically depends on the damping of seismic waves. At some mid-ocean island stations, low seismic damping is necessary to reproduce the observed high level and smoothness of noise time series that result from a spatial integration of sources over thousands of kilometers. In contrast, some coastal stations are only sensitive to noise within a few hundreds of kilometers. This revelation of noise source patterns worldwide provides a wealth of information for seismic studies, wave climate applications, and new constraints on the possible directional distribution of wave energy.
SN  - 2156-2202
UR  - http://dx.doi.org/10.1029/2011JC006952
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=845), last updated on Fri, 05 Jul 2024 23:56:49 +0200
ID  - ArdhuinFabrice2011
ER  -