A seismologist investigates the propagation of seismic shear waves (S-waves) as they travel across a geological boundary from a layer of granite into a layer of limestone.
State the wave equation relating wave speed, frequency, and wavelength.
As the S-waves cross the boundary from the granite into the limestone, their propagation speed decreases. State which property of the wave (frequency or wavelength) remains constant, and explain why the other property must change.
S-waves in the granite layer travel at a speed of 3.0×103 m s−13.0 \times 10^3\text{ m s}^{-1}3.0×103 m s−1 with a wavelength of 120 m120\text{ m}120 m. In the limestone layer, the wave speed decreases to 2.0×103 m s−12.0 \times 10^3\text{ m s}^{-1}2.0×103 m s−1. Calculate the wavelength of the waves in the limestone layer.
