Does the size of an earthquake affect the speed of a tsunami?
The deeper, the faster. The formula for a tsunami wave is speed = [square root of] gravity x depth. Gravity is the gravitational constant of 9.82 meter/second square. Depth is the ocean depth. Which means that the only thing the speed of the wave depends on is the depth of the ocean. It doesn’t matter how strong the earthquake was, the speed of the wave only depends on the ocean depth.