What Makes Waves in the Ocean?
Most waves in the ocean are caused by the wind. Somewhere, far out at sea, wind ruffles the surface of the water. Ripples form and grow into swells, and finally into waves. The longer and harder the wind blows, the bigger the waves get.
As each wave approaches the shore, its lower part begins to drag on the sloping beach and slow down. The top of the wave keeps moving at the same speed until it finally topples over, or breaks.
Since water covers 70 percent of the earth’s surface, waves are constantly forming at sea and breaking against the shore.
More potentially hazardous waves can be caused by severe weather, like a hurricane. The strong winds and pressure from this type of severe storm causes storm surge, a series of long waves that are created far from shore in deeper water and intensify as they move closer to land.
Other hazardous waves can be caused by underwater disturbances that displace large amounts of water quickly such as earthquakes, landslides, or volcanic eruptions. These very long waves are called tsunamis.
Storm surge and tsunamis are not the types of waves you imagine crashing down on the shore. These waves roll upon the shore like a massive sea level rise and can reach far distances inland.
The gravitational pull of the sun and moon on the earth also causes waves. These waves are tides or, in other words, tidal waves. It is a common misconception that a tidal wave is also a tsunami. The cause of tsunamis are not related to tide information at all but can occur in any tidal state.