Carolina Environmental Diversity Explorations

A blackwater river from sea to source · By Dirk Frankenberg

Central section of Bogue inlet: sand bar without vegetation

Figure 2. Central section of Bogue inlet: sand bar without vegetation (Photograph by the author. More about the photograph)

Figure 2 is a photograph of Bear Island on the south side of Bogue Inlet taken from Bogue Bank, the land that appeared in the distance in figure 1. The dark object in the water is a sand bar formed by sediment that dropped from suspension as flooding tides slowed after passing through the most restricted section of the inlet. Predictably enough, this sand body is called the flood tide delta as it is the flood tide equivalent of the ebb tide delta outline by breakers in figure 1.

Note that there are no breakers here. That is because the flood tide delta is inside the inlet and is therefore not exposed to the full energy of ocean waves. Note also that the sandbar has no plants growing on it. The tidal currents are too strong and too frequent to allow plants to get a foothold here. If you look closely in the right background of the photo, however, you will see that salt marsh extends off the end of Bear Island where the flow of tidal currents is slower than in the center of the inlet.


sediment n.
Solid fragments of inorganic or organic material that come from the weathering of rock and are carried and deposited by wind, water, or ice. Sediments may also be formed from chemical, biochemical, or biological materials. [more]