Comment: 12:04 - 12:59 (00:55)
Source: Annenberg/CPB Resources - Earth Revealed 24, Waves, Beaches and Coasts
Keywords: "Thomas Hartnett", beach, sand, "long-shore current", season, wave, energy, transportation, "sand wave", storm, deposition, erosion
Our transcription: Not only do beaches change continuously as sand is moved through them by the long-shore current, but seasonal changes occur as well.
The beaches change from season to season.
By summertime, the waves are fairly low and gentle, and that has a tendency to drag sand towards the beach and build up the beach and make it broader, wider.
And as it piles up, the sand has a fairly gentle slope.
In the wintertime, though, the larger waves, more energetic waves, pick up that sand, tend to move it offshore, and store it in large "sand waves," almost like underwater sand dunes.
And so the beach becomes very narrow.
What sand is there is very, very steep in slope, and most of the beach is really located offshore finding a more stable position under that bigger storm wave.
Geology School Keywords