Monday, May 25, 2020

5/25/20 Report - Coastal Range Monuments and Changing Treasure Coast Beach Profiles. Mystery Find. Snoop Drone.


Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

Turtle Trail Coast Line With Survey Monument Markers Identified.

There are range monuments all along our coast.  Maybe you've seen some of them.  They have brass caps with location information on them.  The one at John Brooks beach is just to the right of the walkway near where the walkway opens to the beach.  I think you might be able to see it now.  It has been uncovered for a while but could have been covered again.

The above map shows the location of the range markers along the Turtle Trail area.  The Turtle Trail parking lot is between markers R-51 and R-52.  R-52 is south of the parking lot.

The following shows the beach profile at R-52 on Nov. 1972 (blue) and Sept. 2007 (green).


The waterline in 2007 at the mean high water was about fifteen feet farther out than in 1972, but at mean low water, due to the more gradual slope, the water line was thirty feet or more farther out than the 1972 water line.

Here is a closer view so maybe you can see it a bit better.



Of course the slope of the beach is not as steep as it appears in the illustration.  Each square represents fifty feet.

Notice how the 1972 profile has a steep front slope and drops off quickly in the water.  The 2007 profile, on the other hand has a lot more sand in the shallow water.  Because items in shallow water were covered by less sand in 1972, the likelihood of items being washed up onto the beach would be greater at that time, although they could also get pulled back into the water more quickly due to the steeper slope.

Here is what the beach in front of the R-52 monument looked like last Thursday - gradual slope with only some of the renourishment sand remaining at the dunes.


Just South of Turtle Trail Thursday Near Low Tide.
You can see the face of the dunes and the white renourishment sand from the last renourishment project at the back of the beach.

Here is an illustration showing various beach profiles at R-13 for seven different times between 1999 to 2008.  R-13 is a little less than about halfway between the Ambersands beach access and the McLarty Museum.

Frances and Jeanne hit us in September of 2004.  You'll notice a profile taken in August of 2004 (before those storms) and in October of 2004 (after Frances and Jeanne).

On the beach front it looks like the beach was cut back around ten feet after the storms.  But remember by that time some refilling had already happened.  The biggest difference between the August and October profiles is closer to the dunes.

You will see a bump in the October profile about 40 feet back from the waterline, that would probably where a lot of the sand that washed back in piled up forming a new berm.

In the five to ten foot elevation range, the June 2003 profile shows the beach being higher than it was during both before and after 2004 storm profiles.

The July 1999 profile shows the beach front at that location eroded farther back than at any other time.  I would expect the best metal detecting around July 1999 and January 2003.  The front beaches were eroded back and the shallow water had less sand close in.

There is a lot you can learn from these beach profiles, but it helps to know when the beaches were renourished and when major storms occurred.

I could go on for a long time about this type of data, but I'll leave that to you if you are interested.

You can use this link, which was sent to me by DJ.

https://www.ircgov.com/Departments/Public_Works/Coastal_Engineering_Section/Documents/Sector_3_Environmental_Assessment.pdf

Besides the beach profiles you'll find a lot of other information about the beaches and the renourishment projects.

Thanks DJ.
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Bill M. sent me the following.

On Friday I spent most of the day detecting Amber Sands beach.  Going north about a mile, I got into the area where there are lots of iron flakes.  Going further north, I found the item below.   


Mystery Object
Find and photo by Bill M.





It rang up as metal, is only slightly magnetic, is heavy at 9.3 grams, and has what looks like flakes of metal in it.   I've been detecting for years and never found anything quite like it.



As I was working my way back to the stairs, I noticed a large shadow in front of me.  I thought it was a bird, but it seemed to be following me.  I looked up and there was a large drone hovering about twenty-five feet above my head.  It was much larger than a DJI Phantom and had a glass dome over the camera.



I couldn't see anyone nearby operating it but did notice a salvage boat offshore.  I wonder if they were the ones who launched it.



Two mysteries in one day!


What do you think of Bill's mystery find?   An EO perhaps?

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A person wearing a facemask on a wide open beach might at least be reducing the risk of skin cancer.


If you believe Governor Cuomo, the exaggerated and  inaccurate predictions of the IMHE model and agencies were responsible for a good number of the coronavirus deaths in New York.  He said it was because of the dire predictions of an over-whelmed health care system that he demanded the nursing homes accept infected seniors, and that is precisely where a big percent of the deaths occurred.


Expect a two to four foot surf along the Treasure Coast for the next week or so.



TreasureGuide@comcast.net