Tuesday, October 03, 2017

Ocracoke Inlet

A few days ago a reader left this comment and question on our blog: "[I]t seems pretty amazing that Ocracoke Inlet has been opened as far back as we can record... Inlets act more like what you describe for Hatteras inlet; moving, opening, closing, shifting. I wonder if there's a theory about why OI inlet has stayed open as far back as records are kept...?"

The following should help explain why Ocracoke Inlet is unique...from THE NORTH CAROLINA OUTER BANKS BARRIER ISLANDS: A FIELD TRIP GUIDE TO THE GEOLOGY, GEOMORPHOLOGY, AND PROCESSES  (http://core.ecu.edu/geology/mallinsond/IGCP_NC_Field_Trip_Guide_rev1.pdf).

"Oracoke Island is situated on an interstream divide between Pamlico Creek (the riverine system occurring beneath Pamlico Sound during the Last Glacial Maximum) and offshore paleo-watersheds. The Pamlico Creek valley extends beneath Ocracoke Inlet (Fig. 6b*), making this inlet the most stable and long-lived in the Outer Banks system. Ocracoke Inlet is the only inlet that has remained open throughout historic times (i.e., since 1590 – the first map of the Outer Banks)."

*The caption below figure 6b in the report reads, in part, "A map showing the topography of southern Pamlico Sound and the Ocracoke Inlet area as it appeared during the last glacial maximum approximately 20,000 years ago when this area was dry land (based upon seismic data; Mallinson et al., in review). Ancient river channels (blue) were mapped beneath the modern southern Pamlico Sound and the inner continental shelf. Note that Ocracoke Inlet occurs where Pamlico Creek passes beneath the modern barrier island trend, and Ocracoke Island occurs on an interstream divide." (Click on the link above to read the entire guide, and to view figure 6b.)

Today outflow from the mouth of the Pamlico River (not to be confused with Pamlico Creek, a paleo-creek referenced above) continues to help keep Ocracoke Inlet open.

Below is a detail from The 2011-2012 Coastal Boating Guide published by the North Carolina Wildlife Resources Commission. You can see the mouth of the  Pamlico River in the upper left corner of the map. About 25 miles to the southeast is Ocracoke Inlet.












This month's Ocracoke Newsletter highlights several noteworthy staircases in historic island homes. To read the newsletter, and see photos, click here: www.villagecraftsmen.com/news092117.html.

3 comments:

  1. Anonymous7:09 AM

    What a cool map. Map reading skills should be continued to be taught in grammer school. But what is the Restricted area and what is in that circle??? Is its proximity to the inlet a coincidence???

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    1. I don't have an actual nautical chart in front of me, but I am fairly certain that area is restricted because the Cherry Point Marine Air Station uses it periodically as a training strafing area.

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  2. Very cool post! And seeing the topography under the water makes it logical, to me, that it hasn't closed; it's part of an ancient river system that remains in place, draining out to sea. THANK YOU, SIR!

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