A new view of the ocean using sound: Seismic oceanography

Seismic oceanography (SO) is a scientific discipline that studies the physics of the oceans using acoustic reflectivity data collected with multichannel seismic (MCS) systems. The seismic reflexions generated within the boundaries of water masses with different thermohaline properties allow us to reconstruct images of the finestructure as well as mesoscale structures. This acoustic method can sample lateral sections along hundreds of kilometers to full ocean depth, with resolutions of 10-100 m in lateral and vertical dimensions, which covers an observational gap in physical oceanography. I will present in the seminar the principles of the acoustic reflectivity in the water layer and show some examples of thermohaline structures that have been detected with this technique in different areas of the world. I will also present the application of inversion methods in SO, which have the goal of recovering the physical properties of the ocean (temperature, salinity and density) from the seismic data. Regarding the inversion methods, I will present my experience in two of them: i) the processing-deconvolution-approach method, which has been applied in real data and ii) the Full Waveform Inversion method (1D profiles, stack data) adapted to physical oceanography with the implementation of sensitivity kernels for temperature and salinity variables.