Open AccessFrom seismic noise to ocean wave parameters: General methods and validation
Author(s) -
Ardhuin Fabrice,
Balanche Abel,
Stutzmann E.,
Obrebski Mathias
Publication year - 2012
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011jc007449
Subject(s) - geology , seismic noise , swell , seismology , noise (video) , ambient noise level , microseism , wind wave , wind wave model , reflection (computer programming) , significant wave height , meteorology , oceanography , physics , sound (geography) , artificial intelligence , computer science , image (mathematics) , programming language
Seismic noise is an indirect source of information on ocean waves. Using a model of noise generation and propagation, seismic stations can be separated into those that are mostly sensitive to local sea states, and those that integrate sources from a large oceanic area. The model also provides a classification of noise‐generating sea states into three classes. The analysis of Central California seismic noise data, well correlated with local waves, reveals that class I events dominate in summer, caused by a single wind‐sea system, and for which ocean wave spectral levels are proportional to seismic spectral levels to an exponent b ≃ 0.9. In winter, noise is dominated by class II generation, for which coastal reflection is important, with a wave spectral density roughly proportional to the seismic spectral density to an exponent b ≃ 0.7. Sporadic events of class III probably produce some of the strongest noise events in Central California and need to be properly screened. These events are caused by opposed wave systems that are usually the wind‐sea and a swell. This noise classification can be used to improve on the correlation between measured and estimated wave heights (up to r = 0.93 for daily averages). For other locations, where remote oceanic sources are recorded, a significant wave height estimated from the seismic noise compares well with area‐averaged satellite data or wave model results ( r > 0.85 for daily averages). These analyses pave the way for quantitative uses of seismic records, including the reconstruction of past wave climates, and the calibration of wave hindcasts.