Thesis Title: Discriminating between spatial and temporal variations in seismic anisotropy at active volcanoes
- Using a dense observational network and an automated shear wave splitting analysis, we examine local earthquakes occurring in 2008 within 100 km of Mt. Ruapehu.
- We introduce a spatial averaging technique and a two-dimensional tomography of recorded delay times, to observe the spatial variation in more detail. We use this new method to create a benchmark of spatial variations in shear wave anisotropy around Mt. Ruapehu, against which future temporal changes may be measured.
- Data from past deployments of three-component seismometers have been analysed and we identify a transient region of strong anisotropy centred on the volcano during the major magmatic eruption of 1995.
- We also introduce a method of analysing temporal variations in seismic anisotropy at active volcanoes by using tight clusters of earthquakes and highly correlated multiplets.
- Finally, we apply some of these methods to data from the 2008 eruption of Okmok volcano, Alaska.
To access my thesis please go to http://researcharchive.vuw.ac.nz/handle/10063/1849 or download it here (324 MB)