I'm looking at an approximation of the average speed of seismic wave towards the center of Earth.
The horizontal path of the waves that affects us directly is well documented, but there is not much about the vertical propagation of such waves.
Of course that speed depends upon many factors like
- depth of the earthquake hypocenter
- magnitude of the earthquake
- Earth strata at the hypocenter
- specific topology of the many layers up to the center of Earth at this location
and this is a complex area, but a rough approximation would be appreciated.
(speed, validSpeedForThatKilometers) = speedAtDepth(hypoDepth,mag,desiredDepth)
or even better a more complex function that would directly give the rough time to reach depth desiredDepth based on some parameters
time = getTimeToReachDepth(hypoDepth, mag, desiredDepth)