On the feasibility of regional Centroid-moment-tensor in the Australian continent and its continental shelf

Abstract:

We present an experiment on the feasibility of using a range of Earth models to calculate the centroid-moment-tensor (CMT) solutions of moderate earthquakes on the Australian continent and its continental shelf. Some recent studies have already shown the benefits of using the 3D Earth models on the CMT solutions of the moderate and large earthquakes surrounding Australia (Hejrani et al. 2017) and the 2016 Petermann Ranges earthquake in the Australian centre (Hejrani and Tkalčić 2020). We expand this work by testing the feasibility of both local 1D models and the regional, 3D AusREM model (Kennett and Salmon 2013) for selected moderate earthquakes with magnitudes larger than 5.5 that occurred in 2010 – 2020 on the Australian continent and its continental shelf. This study lights on the path toward regional CMT catalogues using 3D Earth models at frequencies up to 0.1 Hz which is significantly higher than the frequencies used by global CMT projects like GCMT. We investigate the possibility of CMT inversion for earthquakes smaller than 5.5 as well.

We use data from two permanent networks in Australia: The Australian National Seismic Network (AU) operated by Geoscience Australia and the Australian Seismometers in Schools (AuSIS) network operated by The Australian National University and supported by AuScope.