Explaining Sea Isle City’s “Sinking Beach”
Cape May County went viral yesterday, when a video surfaced of Sea Isle City beach literally crumbling into the ocean. From a sinkhole, to a new jetty, to sea level rise, people seem to have many theories on why this happened. I’m once again going to put conspiracy to rest.
Near the Townsends Inlet, where this video was shot, sand moves south. At each outgoing tide, sand is ripped away from the southern tip of Sea Isle. However, an equal amount of sand is deposited there during each incoming tide. Therefore, this section is in a state of equilibrium.
While freak events such as Hurricanes and nor’easters may temporarily throw this process off, it remains relatively constant. In rare instances, several variables may combine to create an extreme outcome, as we see in this video.
Sea Isle City is currently undergoing beach replenishment. Approximately 510,000 cubic yards of sand is being deposited on the beaches from 75th Street to 93rd Street by the Townsends Inlet. This alone would create an impressive situation, but add a higher tide cycle, and the scenario becomes extreme, as seen in this video.
In New Jersey, high tides range from 3.5’ to 6.0’. When the tide cycle is on its lower end, less flow is required to adequately fill up the bay. When the tide cycle is higher however, significantly more water needs to squeeze through the channel to fill up the bay. For instance, the average high tide two weeks ago was 3.7’, while yesterday, when this video was taken, it was a 5.5’. Since we’re in a higher tide cycle, while rare, these things do happen. Added to the fact that 510,000 cubic yards of sand was just placed down updrift of this location, these processes get intensified.
Explaining Sea Isle City’s “Sinking Beach”