Can anyone with a background in oceanography help me understand the mechanisms that would enable this event to occur? Was this a case where the bulk of the ori

Can anyone with a background in oceanography help me understand the mechanisms that would enable this event to occur? Was this a case where the bulk of the original sand that had been lost in 1984 was trapped offshore in a location that was generally untouched by wave action? Or is this a case where an entirely new set of sand was deposited from some other location?