Towards utilization of full wavefields in ambient noise correlation ~ Field application at the Netherlands and Antarctica ~
Great success of ambient-noise correlation and tomography is founded mainly by the usage of fundamental-mode Rayleigh waves. These types of wavefields have been used for regional, crustal, and more local scale imaging. Although fundamental-mode Rayleigh waves might be one of the most coherent waves we can extract from ambient noise, and hence easy for us to use, ambient noise contains many other types of waves, such as higher-mode surface waves, P and S body waves, reflected and refracted waves, and multiply scattered waves. Extracting and using these waves have great potential to enlarge our imaging areas, enhance spatial/temporal resolution, and improve our interpretation of elastic media. Here I discuss the possibilities and difficulties to use such wavefields. To demonstrate, I use ambient noise data recorded at the Groningen gas field, the Netherlands and at the WAIS divide at the Antarctica. Waveform information can provide higher spatial and temporal resolution of the structure of interest. Also I share recent update of the stationary analysis in which pre-processing can general pseudo events that can be interpreted as reflected or coda waves.