Seismic noise is recorded by broadband seismometers in the absence of earthquakes. It
is generated by the atmosphere-ocean system with different mechanisms in the different
frequency bands. Even though some mechanisms have been known for decades, an integrated
understanding of the noise in the broadband period band 1-300 sec is still missing. The
purpose of the PhD is to use novel theoretical, numerical and signal processing methods to
provide a unified understanding of the noise sources and quantitative models of the broadband
Most noise sources are located in the oceans, they vary over time and many sources
continuously generate seismic waves that propagate within the Earth in the broadband period
range 1-300sec. Depending on the period range, the source can be created by mutual
interactions of ocean waves or by the interaction of waves or infragravity waves with the
bathymetry at the coast.
Body waves provide useful information on noise sources but they are not directly
visible on seismic records because they are weak signals. The purpose of the PhD is to
develop novel signal processing and inversion tools and to apply them to detect body waves
in a data mining approach. The objective is to obtain spatio-temporal models of the sources.
These models will enable to better understand the noise generation in the broadband
frequency range. They will also be used to improve ocean wave models.
The second part of the PhD will be dedicated to the modelling of noise considering
seismic propagation in 3D Earth and to investigate the generation of the different waves, in
particular SH body waves and Love waves