Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.
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If you use the following link and browse around that site, you'll be able to find some of those studies.
Here is a link to a nice animation of that site. When you get to the site, click on the multimedia section to view the animation showing the moving sandbar. You might want to repeat it a several times.
(Animation by Jack Cook, Woods Hole Oceanographic Institution)
The location of sandbars can protect or endanger the face of the beach. As undertow drives sandbars away from the shoreline and further out to sea, waves break further from the shore. When sandbars are pushed closer to shore, waves break closer and run further up the beach. (From the Woods Hole site.)
I took some clips from the animation and added some things. I added the two vertical lines so you could better estimate the position of the moving sand. Orange dots illustrate coins.
In the first clip shown below, the sand bar is out and the currents are moving the sand in, but not the coins. The arrows indicate the direction the sand is moving.
When the sand bar moves in, but the water velocity is not sufficient to move objects such as coins, the coins that were originally lost on the bar when it was out end up in deeper water (see below). Objects lost in the dip in front of the sand bar (above) get buried, as shown below.
Compare the second picture to the first and note the relative position of the coins. There are also times when the coins will move as well as the sand, but that isn't the situation illustrated here. It is about trigger and drop points again. Water force can be sufficient to move just sand or strong enough to move both sand and other objects. Sand and coins can move at different times, and at the same time but at different speeds.
Sand bars are generally moving, sometimes very slowly. As I've said before, items lost on the eroding side will be uncovered if they were previously covered, while items recently lost on the other side of the bar will get buried when the sand is moving in that direction.
Here are a couple more clips from the animation. These show situations where the undertow moves the sand out.
If you are aware of the sands position and how it is moving, that is a big step towards knowing where you'll find objects when you are metal detecting in shallow water. Sometimes objects get uncovered and sometimes buried, and sometimes the objects are moved too.
Whichever way the sand is moving, objects are moving in some relation to that, again depending upon the trigger points and drop points of the sand and objects.
I hope the illustrations are clear and helpful. I had a hard time getting them fixed the way I wanted, and still didn't get it exactly like I wanted.
The Treasure Coast waterway cleanup will take place July 25. I hope you will support this. Anyone can volunteer. It would be a great thing for clubs.
Here is the link for all the information.
Nestled in a north Georgia forest, over 4,000 classic cars decorate 32 acres that have been turned into a junkyard museum. Owner Walter Dean Lewis' parents started the business in 1931 as a general store that also sold auto parts. Lewis grew the collection, which had just 40 cars in the '70s, over time...
I can't believe it. That little two foot bump in the Treasure Coast surf predictions for next week has disappeared. We're back to one foot for who knows how long.