Ocean waves, particularly a type known as swells, can travel incredibly long distances across the globe.
Swells, which are organized wave groups that have traveled out of their original storm source, are capable of journeying thousands of miles across the open ocean.
Understanding Ocean Swells
Unlike choppy, wind-driven waves found near the shore, swells are characterized by their smooth, regular appearance. They form in distant storms where strong winds blow over large areas of water for extended periods. Once outside the stormy area, they continue traveling as organized groups.
According to one reference, swells:
- Organize into groups that are smooth and regular in appearance.
- Are able to travel thousands of miles unchanged in height and period.
- The longer the wave, the faster it travels.
This remarkable ability to travel vast distances without significant loss of energy means that waves you see breaking on a beach could have been generated by a storm located thousands of miles away days or even weeks earlier.
The Journey Across the Ocean
The journey of a swell begins with energy transfer from wind to water. As the waves move away from the wind source, they sort themselves out by wavelength (or period) – a process called dispersion. Longer waves travel faster than shorter ones, leading to the organized lines of swells observed far from shore.
Because they are no longer being affected by the turbulent winds that created them and are traveling in deep water, swells lose very little energy. This efficiency allows them to maintain their height and period over extreme distances, covering thousands of miles before eventually interacting with shallower water near a coast, where they break.
This incredible travel capability highlights the interconnectedness of the global ocean system, where energy generated in one part of the world can literally propagate to another.
