3:00 PM - 4:00 PM
[S18-P-03] Toward probing the deep Earth's interior using spiral-arm arrays and principles of seismic interferometry
The observations of different PKP branches on single seismograms have so far provided the primary dataset for studies of the Earth's deep interior. This dataset sheds light on many aspects of the structures and dynamics of the lowermost mantle and the inner core, such as topography of the core boundaries, or anisotropy of the inner core. Yet, the spatial coverage of these deep parts of the Earth is still far from perfect. For example, the sampling of the inner core by ray paths nearly parallel to the Earth's rotation axis (polar paths) is inherently limited due to the predominant concentration of major earthquakes at tectonic margins.
Here we focus on exploring the use of core-sensitive phases that are not widely detectable due to high noise level. Our initial approach is to utilize the array datasets collected across Australia, including three recently deployed spiral-arm seismic arrays: SQspa (in Southern Queensland), WAspa (in Western Australia), and PSAR (in Pilbara Craton, Western Australia) and the L-shape Warramunga Array (in Central Australia). The arrays are at the epicentral distance range of approx. 20-50 degrees to the majority of significant earthquakes from Southern Pacific subduction zones. We target the compressional waves that get reflected or refracted from the Earth's internal boundaries. We deploy numerical modeling with spectral element methods and array methods to verify the observations. We also test the feasibility of the seismic interferometry principles on the array data by generating virtual ray paths probing the inner core in different directions.
Here we focus on exploring the use of core-sensitive phases that are not widely detectable due to high noise level. Our initial approach is to utilize the array datasets collected across Australia, including three recently deployed spiral-arm seismic arrays: SQspa (in Southern Queensland), WAspa (in Western Australia), and PSAR (in Pilbara Craton, Western Australia) and the L-shape Warramunga Array (in Central Australia). The arrays are at the epicentral distance range of approx. 20-50 degrees to the majority of significant earthquakes from Southern Pacific subduction zones. We target the compressional waves that get reflected or refracted from the Earth's internal boundaries. We deploy numerical modeling with spectral element methods and array methods to verify the observations. We also test the feasibility of the seismic interferometry principles on the array data by generating virtual ray paths probing the inner core in different directions.