Automatic Shear Wave Splitting Measurements at Mt. Ruapehu Volcano, New Zealand

摘要

This thesis presents an automatic shear wave splitting measurement tool and theresults from its application to data recorded in the vicinity of Mt. Ruapehu volcano onthe North Island of New Zealand. The best methodology and parameters for routineautomatic monitoring are determined and approximately 10,000 events are processed.About 50% of all S-phases lead to measurements of acceptable quality. Resultsobtained with this technique are reproducible and objective, but more scattered thanresults from manual measurements.The newly developed automatic measurement tool is used to measure shear wavesplitting for previously analysed data and for new data recorded in 2003-2007. Incontrast to previous studies at Mt. Ruapehu, we have a larger and continuous dataset from numerous three-component seismic stations. No major temporal changesare found within the new data, but results vary for di erent station locations.I