Are amplitudes, mode conversions, or curved rays included?

No. Only schematic travel times for reflected and head branches of P and S, with an independent (v_S1, v_S2) pair; the envelope is the fastest of those four branches at each offset.

Layered Medium: P/S Fronts & Hodograph

P- and S-waves share the same two-layer straight-ray geometry: a reflected leg through the upper layer and, when the basement is faster, a head wave along the interface after the critical distance. The hodograph plots each mode’s branches; the lower panel is the minimum time over the four body-wave branches at each offset (kinematic sketch only).

Who it's for: Introductory geophysics or exploration seismology students.

Key terms

Head wave
Critical refraction
Hodograph
Layered medium
S-wave

Straight-ray two-layer model; default v_S ≈ 0.57 v_P is typical order-of-magnitude for crustal rocks, but you should tune both pairs independently.

Live graphs

How it works

Layered-earth cartoon: P and S head waves when the lower layer is faster; hodograph (t–x) shows crossover between reflected and head branches and the fastest body-wave arrival.

Frequently asked questions

Are amplitudes, mode conversions, or curved rays included?: No. Only schematic travel times for reflected and head branches of P and S, with an independent (v_S1, v_S2) pair; the envelope is the fastest of those four branches at each offset.