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The
Dynamic Landscape of the Outer Banks - continued -
The Outer Banks
is a dynamic landscape. The wind, ocean currents and storm surges from
hurricanes continually reshape the sands on and around these barrier
islands. Sometimes this can be a sudden dramatic change, or it can be
slow and subtle, taking years, or decades to become obvious.
To illustrate
this, I assembled two 1990 aerial photos of the Oregon Inlet area
from the (National
Geodetic Survey, National Ocean Service, NOAA, and then attempted
to overlay the lower part of the 1879
Currituck Beach to Oregon Inlet Chart No. 138 from the Office
of Coastal Survey, National Ocean Service, NOAA archives. Because
the photos and chart were aligned on different azimuths, I rotated
the chart until it matched the photos.
Knowing the current Bodie Island Lighthouse was completed in 1872,
its location would be accurately portrayed on the 1879 chart. Using
the lighthouse as an accurate point of reference, I aligned the
chart and the aerial photo until I found a perfect match. I was
quite surprised to find so many land features which remained virtually
unchanged during the 111 year span between the chart and the photos.
Note Cedar Island, Cedar Point, and the shoreline and creeks south
and east of the Bodie Island Lighthouse have changed little. This
allowed me to verify my alignment with several stable land features.
The images below are clickable, and will show a large version of
each of these images.
- Image One - A scaled down view of the bottom portion of the
1879 chart. Click here for
an even larger, more detailed version of the chart (103KB file).
- Image Two - These are the two aerial photos combined before
the chart was overlayed.
- Image Three - This shows the photo overlain with the chart,
but the dark lines tend to obscure part of the photo.
- Image Four - This shows the chart overlain, but partially
transparent, so the photo underneath can more easily be seen.
Although much of the chart and photo matches, it is obvious that
the beach tends to move inland, the sound side of the islands do
change, and that Oregon Inlet has moved and changed a great deal
in the 111-year span of time represented here.
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1
Note:
The chart above shows only the tip of Pea Island on the south side
of Oregon Inlet. |
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After having
such success with the 1879 chart, I looked at an 1862 chart of
Oregon Inlet, also from the OCS/NOS/NOAA archives. Noting its scale
1/20000 was the same as another set of 1990 aerial photos from
NGS/NOS/NOAA, I assembled three of the 1/20000 scale aerial photos
around Oregon Inlet. But after comparing them to the 1862 chart,
I had no real hope of being able to match the land forms. And since
the Bodie Island Lighthouse was in a completely different location
in 1862, even that landmark would not help.
But when I made the effort to overlay and align the chart with
the aerial photo, my pessimism proved unfounded. Some of the same
features which allowed me to align the 1879 map were still valid
for the 1862 map. Cedar Island, Cedar Point, and the creeks and
shoreline around where Bodie Island Lighthouse now stands were
completely recognizable even after 128 years. The results are shown
below.
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Click on diagram
for larger view.
Diagram by Fred Hurteau. |
Direct Comparison
I created this diagram in which the 1862 and 1879
charts have been reduced to simple solid color shapes, and overlain
to compare the changes in the geography. Three things become easy
to see:
- Extensive beach erosion has moved the beach inland east of
Bodie Island Lighthouse.
- The sound side of the barrier island is quite stable, including
islands and creeks. Note how well the yellow and red overlays
match around the lighthouse.
- There has been considerable movement southward of Oregon
Inlet.
In just seventeen years, from 1862-1879, Oregon Inlet had moved
drastically. In fact, the location where Bodie Island
Lighthouse stood in 1862 is smack in the middle of Oregon
Inlet just 17 years later. It's no wonder a new site had
been chosen when Dexter Stetson started construction on
the current Bodie Island Lighthouse in 1870 just after
completing the current Cape Hatteras Lighthouse that same
year. It is also why the Cape Hatteras Lighthouse had
to be moved 129 years after Dexter Stetson finished.
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