What characterizes P-wave arrivals on the far side of the Earth at epicentral angles beyond 140°?

Question

Quizplus · Accepted Answer

P-waves that reach the far side of the Earth beyond 140° epicentral angle are slowed down by around 40% due to refraction through the outer core, which is partially liquid and has a lower seismic velocity than the mantle. This phenomenon is called the "shadow zone." The Ni-Fe in the core does affect the behavior of seismic waves, but it does not amplify P-wave arrivals on the far side of the Earth. P-waves do arrive sooner than expected at the mantle-core boundary, but this is not specific to epicentral angles beyond 140°. The waveform of P-waves is not inverted on the far side of the Earth.

What Characterizes P-Wave Arrivals on the Far Side of the Earth