Phys.org  August 17, 2024 Seismic energy arriving before the compressional (P) wave passing through the core (PKP), called PKP precursors, have been detected for decades, but the origin of those arrivals is ambiguous. The largest amplitude arrivals are linked to scattering at small-scale lowermost mantle structure, but because these arrivals traverse both source and receiver sides of the mantle, it is unknown which side of the path the energy is scattered from. To address this ambiguity, an international team of researchers (USA – University of Utah, University of Arizona, UK) applied a new seismic array method to analyze PKP waveforms […]