Abstract:
Ocean wave and microseism properties, and particularly their generation, are studied through the analysis of long term recordings made in the Taranaki and Gt Barrier Island regions. Two years, 1980 and 1981, of ocean wave and microseism data recorded at both sites were spectral analysed and meteorological data acquired from both the NZ Meteorological Office and the field sites were processed for this purpose. Sections of data recorded outside these two years and on Chatham Island were also analysed.
Fetch-limited ocean wave generation in the South Taranaki Bight is studied and a characteristic fetch limited spectral shape and growth rate established. From this a time dependent spectrum model is derived and compared with a number of ocean wave growth events.
Microseism generation is studied by comparison with the locally recorded ocean wavefield. A number of generation events are analysed and a comparison is made with present theory. From this the ocean wave regimes which are responsible for the microseism generation are established, and the theories of microseism generation verified.
The propagation characteristics of the microseism are analysed by way of spatially separated seismic noise recordings and direction of arrival measurements. This, along with the results of the earlier studies in the thesis and the fundamental statistics of ocean waves and microseisms are used to assess the potential of a land based ocean wave meter.
A comment is also made on the general climate at the two main sites for the years 1980 and 1981.
These two sites will be reasonably characteristic of the general wave fields on the east and west coasts of New Zealand.
