Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.
I'm going to put some things together today. Back in 2015 I did a post on five ways I've seen coins move on a beach. I listed the following five ways.
1. Fall out of an eroding cliff, cut or dune.
2. Slide down the face of a cliff or dune.
3. Move within a rush of water.
4. Roll down a slope.
5. Flip.
There is another I did not actually observe on the beach, but I've seen demonstrated in a wave tank. Under the right conditions coins will do what I will call "step."
When a coin is on a slope and the flow of water is up the slope, sand on the downhill side of the coin will be gradually eroded until the coin slips down one step, stop, and then take another step when the sand erodes from the downhill side again. A step is not more than a coin length.
People often talk about the weight of an object determining how objects move on a beach, but weight is only one factor. And coins seldom really sink. Usually they fall into areas where the sand has left. That might sound like the same thing, but to me there is a big difference. Normally coins are not drawn by gravity through stable layers of sand.
To illustrate something important, as I've said several times before, a ton of Styrofoam will still float even if it weighs a ton. Its weight does not cause it to sink in water. Density is more relevant. But the density of the object is not the only characteristic that determines how much an object will be moved by a given force of water either.
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| Four Sinkers Used In Experiment. |
I once did an experiment and showed that the shape of an object will have a lot to do with how an object is moved by water on a beach. I took four different lead sinkers (See photo above.). There.were three different shapes. Two were disk-shaped.
I then used a bucket of water to simulate a wave hitting the them. They all moved different distances. As predicted, the oval shaped sinker moved the farthest, followed by the fish-shaped sinker, then the small disk, and the large disk moved the smallest distance.
Here is the link to that post.
https://treasurebeachesreport.blogspot.com/2013/08/8513-report-what-actually-determines.html
When the density is held constant, weight will have some effect, but so will the shape of the object. The larger disk moved less far than the smaller disk, but neither of those were moved as far as the fish-shaped sinker or the oval.
That experiment concerns horizontal movement - movement on a relatively stable surface of sand. But when you have erosion, the sand is moving, and possibly other objects as well. Most of the objects that we are most concerned about will not move as much as the sand, which will be moved by the water more easily and quickly than most of the objects.
Take for example the sinkers shown above. If it was actually a wave, there would be a lot more water, and the sand would be moving too. While the sand was being washed away, items that move less easily would not move as much as the sand. In some cases, those items would remain in the area vacated by the sand.
In other cases, both the sand and other items might move, but some other items will not move as fast as the sand. And some items will move farther than others. It is a matter of the relative movement.
If you've ever noticed, fairly dense coin lines near the water will often show an ordering or classification of coins by denomination. Quarters will be one distance from the water and define one edge and zinc pennies will be on the other side. With the coins having a similar shape and more or less similar density, that is determined by the different weights. However irregularly shaped miscellaneous objects of different metals will be scattered through in a more unpredictable order.
Here are some of the densities of common metals in kg. per cubic meter.
I then used a bucket of water to simulate a wave hitting the them. They all moved different distances. As predicted, the oval shaped sinker moved the farthest, followed by the fish-shaped sinker, then the small disk, and the large disk moved the smallest distance.
Here is the link to that post.
https://treasurebeachesreport.blogspot.com/2013/08/8513-report-what-actually-determines.html
When the density is held constant, weight will have some effect, but so will the shape of the object. The larger disk moved less far than the smaller disk, but neither of those were moved as far as the fish-shaped sinker or the oval.
That experiment concerns horizontal movement - movement on a relatively stable surface of sand. But when you have erosion, the sand is moving, and possibly other objects as well. Most of the objects that we are most concerned about will not move as much as the sand, which will be moved by the water more easily and quickly than most of the objects.
Take for example the sinkers shown above. If it was actually a wave, there would be a lot more water, and the sand would be moving too. While the sand was being washed away, items that move less easily would not move as much as the sand. In some cases, those items would remain in the area vacated by the sand.
In other cases, both the sand and other items might move, but some other items will not move as fast as the sand. And some items will move farther than others. It is a matter of the relative movement.
If you've ever noticed, fairly dense coin lines near the water will often show an ordering or classification of coins by denomination. Quarters will be one distance from the water and define one edge and zinc pennies will be on the other side. With the coins having a similar shape and more or less similar density, that is determined by the different weights. However irregularly shaped miscellaneous objects of different metals will be scattered through in a more unpredictable order.
Here are some of the densities of common metals in kg. per cubic meter.
Aluminum 2712
Brass 8400 - 8700
Copper 8940
Gold 19320
Iron 7850
Lead 11340
Platinum 21400
Silver 10490
Steel 7850
Titanium 4500
Tungsten 19600
Zinc 7135
Brass 8400 - 8700
Copper 8940
Gold 19320
Iron 7850
Lead 11340
Platinum 21400
Silver 10490
Steel 7850
Titanium 4500
Tungsten 19600
Zinc 7135
A gold ring is not only dense, it is also round and open. I've seen gold rings roll down the slope. The opening presents little surface area for the water to push against, which is one reason in addition to the density that gold rings tend to be low on the beach if they have been in the area affected by moving water.
Copper sheathing, on the other hand, despite the relative density, being flat and relatively thin will end up much higher in the sand and on the beach than would be predicted by the density alone.
That is all I'll do today, but there is a lot more to it.
How objects appear to sink over time is another fairly detailed discussion that is not as simple as it might seem. While weight has something to do with it, it is a more about the movement of objects relative to the force of the moving water and the movement of sand.
You'll see a lot of people who will tell you to look one place or another for certain kinds of objects, but they won't explain how they got there, I believe it will help if know how and why those objects ended up where they did.
Here is the link to the post on the five ways I've seen coins move on a beach.
https://treasurebeachesreport.blogspot.com/2015/07/7115-report-five-ways-coins-move-on.html
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I am lucky - very lucky. Long before sunrise I often wake up and smile. It's not that a lot of really good stuff happened to me. I think it is more that I remember good things. They are little things - many from my childhood - when a neighbor kid said or did something nice, for example.
I felt rich, even though we didn't have a lot. Back then I didn't know people who had a lot more.
It must be how you remember things. Or what you tend to remember. I remember the time one neighbor boy stood up for me. The time another chanted my name as I sat on the bench at a high school football game. The time another neighbor boy asked the gym teach to let me stay and play with the older kids. I look back on those things as kind acts, and plan to look up those boys and thank them if I can.
You see, my fond memories aren't of really big things, as most people would judge, but they populate my memories like stars or Christmas lights on a silent night. I'm lucky I remember those things.
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Concerning coronavirus -
Large numbers of people normally die from the flu every flu season, but from what I read, this flu season has been unusually light. Could the unusually light flu season be due to the social distancing and other measure put in place for the coronavirus? Possible, but those precautions have only been in effect for a very short time, and flu season began in Oct.
And the same source said that of the flu and coronavirus deaths, only about 2 percent were due to the coronavirus. I assume that those statistics are based upon comparable time frames, but at this moment I am not sure.
Www.health.com says, While everyone is in a panic about the coronavirus (officially renamed COVID-29 by the World Health Organization), there's an even deadlier virus many people are forgetting about: the flu.
Flu season is hitting its stride right now in the US. So far, the CDC has estimated (based on weekly influenza surveillance data) that at least 12,000 people have died from influenza between Oct. 1, 2019 through Feb. 1, 2020, and the number of deaths may be as high as 30,000.
The CDC also estimates that up to 31 million Americans have caught the flu this season, with 210,000 to 370,000 flu sufferers hospitalized because of the virus...
Just some context, however statistics are not yet complete on this flu season.
I'll try to get you good statistics and references on this.
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The predictions are for a small increase in the Treasure Coast surf - up to three or four feet this weekend.
Enjoy your quiet time as well as your metal detecting,
TreasureGuide@comcast.net
