Wind, mostly. And the moon's gravity, but mostly wind.
the wind
waves
waves
it causes current waves.
Winds and subsea movement of water.
Surface gravity waves not created by wind
Mostly its wind.
The interaction between the atmosphere (air) and the hydrosphere (water) causes waves in the ocean. Wind transfers energy to the water's surface, creating ripples that evolve into waves as they move across the ocean.
Ocean waves are what causes weathering and erosion on the coast. The force of the waves can create cracks in rocks and break them apart into smaller rockogjswziys.
These waves are called "Tsunami" Note , Earthquakes CAN cause giant waves (not all sub sea earthquakes do this). Note also that there are other causes of Tsunami.
Oh, yes. That's one of the biggest causes of Tsunamis, or Tiday Waves.
A submarine earthquake causes a tsunami.