#4 Postby MiamiensisWx » Wed Aug 06, 2008 4:22 pm
In regards to the beach escarpment ("wall"), the local topography and long term accretion trends may play a significant role. I can attest to the fact as well, since I'm another resident along the eastern portion of the peninsula. Many dredged inlets along the east coast of the state have prevented the transportation of sand to locales further south. Sediments were typically transported via the long shore current, as disrupting inlets were not a factor prior to human intrusion/coastal management. I've visited Indialantic and the coastal regions of Brevard County, and research indicates the construction of the Port Canaveral inlet has resulted in decreasing accretion rates on adjacent beaches further south. Consequently, with decreasing accretion rates, erosion has become a much more significant threat in these areas. Indialantic and Cocoa Beach are prime examples. Another factor is the influence of offshore topography, which is constantly "in flux" and changes via non-human and human induced influences. The accretion rates along the east coast of Florida have always varied per each region, which corrobates with the influence of regional/localized topography. These "nuances" could definitely explain the formation of escarpments during minimal tides and wave action. As an aside, I've observed the formation of escarpments during periods of similar wave action to the event depicted in your photograph, so it does not require exceptionally severe wave action, high tides, a coastal/barotropic low, or the influence of a tropical/extratropical cyclone. Escarpments may form more readily on vulnerable beaches with decreasing accretion rates. Beaches that were recently eroded via wave action are also more susceptible to escarpments forming because of minor influences.
I've regularly encountered the "sea turtle nesting location/TC strike" theory as well. Although the behavior of wildlife is a definite and accurate indicator of changing conditions within the short term (i.e. several days prior to a TC), I don't believe it is a correlation with events or patterns beyond this time frame. Animals typically respond to changes in light, cloud cover, temp dewpoints, sea level pressures, and other short term facets. They can detect approaching surface fronts, thunderstorms, tropical/extratropical cyclones, etc. However, as mentioned, this applies to the short term. Any correlation with seasonal (long term) patterns is speculation, and it is likely false, though it is always an extremely intriguing topic of discussion. I believe variations of sea turtle nesting locations during each season is explained by the turtles' ability to detect changes in local topography and conditions at specific beaches. For example, if the turtles return to a specific beach that has experienced erosion during the preceding year(s), they may nest closer to the ocean or avoid that locale. On the other hand, if a relatively stable beach/dune structure is located, the turtles may nest more extensively on that beach. Congregations and densities of nests are greater. Consequently, nest variations are greater as well. In other words, the nests' locations may also expand further inland along the dune as well, when compared to an unstable/eroded beach with decreasing accretion rates.
Hopefully, I cleared the air...
Miami
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