It's not a shock wave, it's a shallow water wave (because the wavelength is much larger than the depth of the ocean). The speed depends on depth [v = sqrt(g*H)]

It's not a shock wave, it's a shallow water wave (because the wavelength is much larger than the depth of the ocean). The speed depends on depth [v = sqrt(g*H)]; for typical deep Pacific (5000 m), that is ~220 m/s or 500 mph.