8/2/19 Report - Good Way To Check The Beach and Some Things to Look At. Different Slopes.

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

Three Views of Same Beach Area Taken Different Days.

Photos captured from beach cams by Alberto s.

Alberto S. sent me the above images along with the following email message.

… with some time available I went looking around the different beach cams online and a turtle nest on one of the places I checked looked to be partially on the slope so out of curiosity I looked back and found the day it was marked and it was showing the slope way in front and not as close. The image includes the dates I checked and it’s clear the slope changed over time, which seems some erosion has taken place even with conditions not favorable, but I suspect not enough. So in trying to learn about interpretation of beach conditions I was wondering if you could share your thoughts.  Your help is always appreciated. 

In case you can't see the dates very well, the top image is dated May30, 2019; the middle one is dated June 29, 2019; and last, July 29. 2019.   Besides capturing each image, Alberto S. added a red line to highlight the berm.

In each image, you can the turtle nest marker, highlighted by a white box.  The turtle nest provides a reference point for estimating the movement of sand relative to the marked nest.  A stable marker can give you a point of reference for more accurate readings.  It appears that the berm was about the same distance away from the nest at the end of May and June, but in July, the berm is farther west and at the turtle nest.

That is an excellent way to watch beach movement in areas covered by a web cam.  Thanks Alberto!

Movement of the berm definitely tells you something.  If the berm is moving that tells you something, but there is more to it.

The beach can move back when it erodes, going from position 1 to 2, or sand can accumulate and the beach move

Illustration of three possible beach front slopes.

That would be simple enough, and eroding beach would recede and an accumulating beach moves out into the water, but that is too simple.  In the beach web cam images, it does not appear that the beach front changed much in slope or shape, however the slope of the beach can change, and that can be important too.

Three hypothetical beach front slopes.

Lets say that 1 represents the normal or average slope.  Line 2 shows a less steep slope.  The berm moves back, but the foot of the slope is actually farther out into the water.   A steeper slope could have the berm farther out towards the water while the foot of the slope is cut back.

All I'm illustrating here is that while the location of the berm is a decent indicator, there are other factors such as the slope and shape of the slope.  For illustration purposes I drew a perfectly straight slope, but that does not happen in real life either.

Other things being equal, which, as I always say, they never are, from the first illustration, I'd most like to see a beach like slope number 2.  The farther back the better.

From the second illustration, I most like number 3.  The steeper the better, and a foot that is back from the normal water's edge.  However, if the gradual slope cut into the back dunes that could be a good one also.

Of course, there are other factors.  I'll perhaps get into those tomorrow or some other day, but knowing the history of the beach is important too. It can be helpful to know how the beach developed over time.  If the erosion is cutting into newly accumulated sand rather than older layers, for example, it is not likely to produce much of anything old.

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The system shown on yesterday's National Hurricane Service map is giving us some rain but won't do much else.

The system out in the tropical Atlantic is not organized, but has plenty of time to develop.  If it does, it could come our way.

TSource; nhc.noaa.gov

The tides are nice and big but the surf is only about two feet.

Happy hunting,
TreasureGuide@comcast.net

2/8/14 Report - A Recent Treasure Coast Cut and Some Hints For Analysis. 17 Pound Gold Nugget Found.

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

Interesting Spot On The Treasure Coast Yesterday.

This picture makes a good illustration.  I'll use it to talk about beach analysis.

The low spot is just a touch above and to the right of the center of the picture.  That would be in the wet sand just behind the bigger rocks.

Cuts were very few and far between that day. This spot was not at all typical.

When I look at a spot like this the first thing I look for after looking at the cut is the low spot in front of the cut.  In this case, the low spot was bordered on one side by rocks.

The cut in this picture is about four feet high and maybe a little more.  As you can see the cut extends to the north a good ways.  It also extends a good ways to the south (out of the picture).

I'd take a look at the bottom of the cliff to see if it is a fresh cut or if it is a few days old and deteriorating.  Also look at the sand in front of the cut to see if the cut is filling yet, and if so, how much.  Check the firmness of the sand in front of the cut.

There are boards sticking out of the sand.  Check them to get an idea of how old they are.  In this case I was disappointed by how modern they looked.  I really should have taken a better look at them and the nails that were in them.   Nails can tell you a lot about the age of the boards.  I didn't take the time to uncover the nails.  That could have been a mistake.

Rocks can function as traps.  Both the rocks and boards can serve as markers, as they are covered and uncovered it will tell you how much sand is being added or removed.  Always take a good look at such markers.  They can provide valuable information.

In this picture you can see a bend in the beach.  Look at any cuts or dips to try to determine how they were formed.  There may be other similar places along the coast where similar cuts were formed.   I'd check other spots south of bends like this one.  Sometimes you'll get a good idea of where other cuts will occur along the coast by looking at how and where one cut was formed.

Just under the top layer of sand was a layer of course but hard packed red/brown shell sand.  You will learn to identify different types of sand and what types of items might be found in them.  That sand had been undisturbed for a good while, but the boards suggested to me that the sand had not been undisturbed as long as I first thought might have been the case when I first saw it.

Watch any spots like this over time.  They can fill or become deeper.  They can move any direction.  By watching the various markers, including boards and rocks, you should be able to tell if the dip is moving one direction or another from one day to the next.

Note when the dip was formed.  What was the wind direction at that time?

When a cut like this is formed south of an eastward bend in the beach, it would normally be a north/northeast wind.   When the wind changes there is a good chance the cut will fill again.

Any cut like this is worth checking out at least briefly.

Today we have a southeast wind.  That won't change until around Tuesday when we'll get a northeast wind again and a bit of a bump in the surf.

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Here is the kind of day you'd like to have.  A herdsman found a 17 pound gold nugget laying on the ground.   Now that is the type of eyeball find I'd love to make.

Here is the link for the whole story.

http://www.marketwatch.com/story/chinese-herdsman-stumbles-onto-a-17-pound-gold-nugget-2015-02-05?mod=MW_story_recommended_tab

Thanks to Leo for sending that in!


Happy hunting,
TreasureGuide@comcast.ne