7/6/20 Report - Tropical Storm Edouard. Beach Zones. Density and Specific Gravity of Things.

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

Yesterday I discussed liquefaction, which can occur on a beach under certain circumstances that cause sand to act much like a liquid.  I showed a couple photos of liquefied sand being moved by big waves.  Of course, most of the time that occurs near the front of the beach, but when the tides and swells are big, it can occur on the back of the beach.

Before delving more into the physical forces that move sand and other objects, this morning I thought it would be useful to mention the various beach zones of interest to the detectorist.  

Starting off-shore in the shallow water, there can be a sand bar.  That can be a good place to metal detect if there are a lot of bathers using the bar.  That happens a lot down in the Fort Lauderdale/Miami area.  It can be a very good place to detect for modern finds or what I call recent drops, but don't forget that the bar will move, and one side or the other, depending upon the direction the bar is moving, can be good detecting.

Inside of the bar, is often a dip, which can also be good detecting.  In fact some of my best detecting ever was in a cleaned out dip.  The dip can be full of sand and shells, but it can also be cleaned out down to bedrock, which of course is when the detecting can get very good.

On the beach front in the wet sand can also be good detecting, but it can also be poor, depending upon what is going on.  This area can be good or poor, depending upon a variety of factors, especially whether the sand is building on the beach front of eroding.  In either case, good water action can wash up good targets.  In the wet sand below the berm you might be able to find the coin lines or coin holes that I've mentioned many times.  They can also have other good targets beside coins.

The fourth zone is the dry sand area, which of course can be good if people have been using it.  Hunting the dry sand is very different from hunting the wet sand or water because the water does not do as much sifting and sorting there.  Detecting in the dry sand depends more on where things were dropped.  In the wet sand things gets sifted and sorted more, so you are often looking more for where targets ended up rather than where they were lost.  The water does however hit the wet sand area on some occasions and can definitely affect the distribution of finds.

The fifth zone is the dunes, where you will usually not be allowed to hunt.  Very old items will typically be buried a foot or more in the dunes, but when the water hits the dune face, items can be washed out and onto the flat beach.  

It can get a lot more complicated but those are some of the basics of the five zones.

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We often talk of where you might find heavy items like gold.  As I've said many times, it is really not the weight that we are concerned with.  A ton of Styrofoam will float.  It is more a matter of density, rather than weight.  Other things are important too though, such as the shape of the object.  Bend tons of steel into the shape of an ocean liner and it will float.

Here are the densities of some of the metals you might find.  That helps explain why you can find aluminum when beach conditions are not very good, and why lead is a good sign if you are looking for beach gold.

Again, shape is also important.  Shape a super tanker out of steel and it will float.  Thin sheets present more surface area for the water to push around or lift.

Specific gravity is the density of an object relative to the density of a reference substance, usually water at a specific temperature and salinity.

Having a specific gravity of 19.32, gold is over 19 times more dense than reference water.

Sand has a specific gravity of somewhere around 2.65 to 2.70.   So being more dense than water it sinks in water.  There are a variety of other forces at work on the beach sand though, and the shape and constitution of the sands makes a difference too.

Notice the specific gravity of aluminum is very close to that of sand, so it is no surprised that you can find it in sand that is building on the beach.

Another generality is that it will take a lot more water force to move gold than either sand or aluminum.

If you understand these things it will help you figure out how things are moving and that will give you a better idea of where they might be found.

One of the things about gold rings is the relative lack of a flat surface area for the force of water to act on.  A copper coin on the other hand, will move differently than a gold ring not only because of the different density of the material but also because of the shape.  Likewise the movement of a zinc coin will be determined in part by the adherence of materials to the surface of a corroded coin.

That will provide some background for future discussions.

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As I said yesterday, the National Hurricane Center map is starting to light up.  There is now a tropical storm :Edouard.  Edouard will not affect us, but there is a new system down by South America to watch.

Source: nhc.noaa.gov

It is the time of year to start watching for storms.

Happy hunting,
TreasureGuide@comcast.net

3/29/20 Report - Beach, Sand and Water Movemnts. Treasures in Books. Coronavirus Migrations.

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

I've been thinking about presenting this topic for a long time, but it is difficult to present.  There are so many variables and it is so complex that it is hard to illustrate and explain.  Everything I am going to present is simplified, but that is the way it has to be.

It does NOT apply to steep areas or areas that the waves are breaking on.  It applies mostly to the mid and back beach areas that are only gently sloped.

If you talk about coins or things sinking at the beach, one way to visualize it is like objects sinking in water.  In other words, gravity would pull them down to a lower level without anything else happening.  That is not how it happens in sand.

You can set a coin or ring on the sand and it is not going anywhere unless the sand is agitated.  Try it for yourself.  It doesn't matter how long the object sits on the sand, it isn't going anywhere unless you stir things up.

Illustration A, which shows three objects on the beach.  They are going to sit there until the sand moves.  Assume the objects all have the same shape and size and density and the force of the water is enough to move the sand but not the objects.   If six inches of sand is removed from that area of the beach, the objects will then be down about six inches and on the new surface (NS), as shown in illustration B.

They will stay there on the new surface until more sand is moved from under them (again the assumption is that the water force is enough to move the sand but not the objects).

If more sand is moved while the force of the water is not enough to move the objects, the objects will drop down some more.  Remember, I'm oversimplifying here.  However if the sand returns (while the water force is still strong enough to move the sand but not the objects, the objects will get covered.  If six inches of sand moves, but this time in the opposite direction, the objects will be under about six inches of sand.

This coming and going of sand can happen many times.  If the amount of force is only great enough to move the sand, we will have some idea how deep the objects that started near the original surface will be.  If additional layers of sand are moved (without the objects being moved horizontally) the objects will find the lowest layer where the sand had vacated.  If, for example, three times six inches of sand was removed without any sand refilling, the objects will be down about 18 inches.  In actuality that would be unusual.   More commonly you would see sand eroding and then refilling to some extent in between erosion events.

My observations of local beaches seems to show that a foot or two is really about as much as you'll usually see, and that amount can put you into productive sand, and likewise cover it up when the flow of sand reverses.

More than a 100 times to 1 some amount of sand will be left covering the newly settled objects.  Only when a slight wash of water, most often during a descending tide, uncovers the items will the items be exposed and laying right on the surface.

I haven't even addressed when the water force is strong enough to move the objects too.  In that case, the objects, either a few or all of them will be moved some distance with the sand, but usually not as far as the sand.  And if the objects have different densities, sizes or shapes, they will also separate.

Another complicating factor is the fact that the water will be usually coming in and then reversing and going back out over the same area.  That means that in those cases the sand and any other objects can be moved in both directions.  The relative force of the incoming and outgoing water will determine which objects are moved how much, and the important thing - the net movement.  An easily moved object will can move a large distance in both directions, but one direction more than another.  Sometimes other factors come into play, such as the slope or other obstacles.

Objects that move less easily will remain closer to their original spot.  But there are also times such as when you have a good angle that the water comes in and washes out at more of an arc, which means a steady movement either south or north will be observed rather than only the back and forth of the up and down hill movement.

Back to the simple case in which we only consider a single sand moving wash of water.  The main point is that less easily moved objects fall into lowest layer and will tend to remain there, periodically being uncovered a little and then covered more deeply again.  They'll mostly stay at the same level until the sand gets moved and they reach a new lower level.  That might sound like sinking, but it is not sinking into a stable layer of sand.

When you can identify an old layer of sand that has been exposed, it likely has been relatively unmoved for a long time.  It will take an unusual event for it to be washed out - yet it does happened.  Usually when such a layer is near the surface it will get covered fairly quickly again and then most future movements of sand will be the coming and going of the one or two feet above that, but not much more.

If the objects are in deep layers that haven't been exposed for long periods of time, they will probably remain there for long periods of time.  It will take an unusual event to expose once again those deep layers.  And if items get down to bedrock and caught in crevices or whatever, they will stay there until some very dramatic event occurs or somebody removes them.  It will take a very unusual event, probably a sequence of events, to dislodge them naturally.

I started out trying to be specific, but couldn't cover much that way, so I got more general.  Like I said at the beginning, there are a lot of variables and it isn't simple.

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Carpintero was working as an intern at the Z.D. Ramsdell Civil War Home Museum in Ceredo, West Virginia, when she discovered the letter tucked in a book. The letter, dated June 27, 1862, was written by then Lieutenant McKinley of the 23rd Ohio Infantry to Ramsdell. Carpintero found the letter Jan. 7 while researching another artifact in the museum and said her internship supervisor was just as surprised by her finding the letter as she was.

Here is the link.

https://www.herald-dispatch.com/wcn/wc_news/student-finds-letter-written-by-former-u-s-president-at/article_fbef0ecf-4267-5fcb-84ae-87eb74b1ef3c.html

I've written before about the surprises you can find in books.  I once wrote an article about that for a treasure magazine.

I have many old collectible books (over a hundred years old) that have never been read.   How can I tell?  The pages have never been separated.  They were never trimmed.

Old books are one of my favorite treasures, but unlike back forty or fifty years ago, the collectible book market is not good except for the most desired books.

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Population migrations are interesting and often result in good places to detect.  Ghost towns are one good example.

Here is a link to an article about the coronavirus migration.

https://www.msn.com/en-us/news/us/the-great-american-migration-of-2020-on-the-move-to-escape-the-coronavirus/ar-BB11QAma?ocid=spartandhp

A few days ago I mentioned that people are escaping the high-risk New York area that has around fifty percent of the nations confirmed cases.  Instead of self-isolating that are spreading the risk.  There was some talk of stopping that, but it was those with means that were doing it, so it wasn't stopped.

Some local areas did take measures to stop it even if the governors didn't want to.

...From beaches and resort towns to mountain cabins to rural family homesteads, places far from densely packed cities are drawing people eager to escape from infection hotspots. But virus fugitives often are running into fierce opposition on their routes, including Florida’s effort to block New Yorkers from joining their relatives in the Sunshine State, a police checkpoint keeping outsiders from entering the Florida Keys, and several coastal islands closing bridges to try to keep the coronavirus at bay... 

...As the threat of the virus intensified last week, Danette Denlinger Brown, 54, hoped to relocate from Williamsburg, Va., to North Carolina's Outer Banks, where she and her husband own a second home. But as she prepared to leave, she learned that North Carolina police had blocked the Wright Brothers Memorial Bridge connecting the mainland to the barrier island. Only year-round residents could cross, a restriction county officials said was necessary to stop migrating families from overwhelming the area’s only hospital, a 20-bed facility...

They tell those who are moving to self-isolate for fourteen days, but who takes with them two weeks of supplies when they travel.  It's a farce.  Cuomo is happy to export his problem to another state, along the needs and statistics that go with them.

As per the TV news, there are so many private jets from New York now at the Palm Beach airport that there is no more parking space.

The blue state elites are now escaping to the culturally backward blue-collar red states for refuge.  Actually those who could always did.

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The surf will increase to 3 - 5 feet in a few days.



Act responsibly not selfishly.  Think of others as much as yourself.
TreasureGuide@comcast.net

3/24/20 Report - More On Beach Dynamics and How Various Objects Move On The Beach. Remembering.

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.

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.

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

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

12/27/14 Report - Baby Ring. Finding The Density Of An Unknown Object. Hoard of Blades. Le Griffon Shipwreck. St. George.

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

Baby Ring.

Yesterday I showed a heavy pendant.  This is a small item - only .025 troy ounce. 

It is less than a size 2.

You might want to get a mandrel so you can determine the size of rings you find.  They are not expensive. 

This one acid tests as gold filled. 


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Yesterday I mentioned calculating the density of objects to help determine the composition.

Here is a web site that explains the basics.

http://van.physics.illinois.edu/qa/listing.php?id=806

And here is a table of densities for most common metals.

http://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html

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A hoard of sword and knife blades was found by a detectorist. 

Two blade fragments, a scabbard fitting, a multi-edged knife and six copper ingot fragments were discovered by Adrian Young a few metres apart...

Here is the link for more of the story.

http://www.culture24.org.uk/history-and-heritage/archaeology/art511370-exotic-hoard-artefacts-found-in-field-hint-at-long-distance-bronze-age-sea-travel-say-archaeologists-in-wales

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Le Griffon vanished in 1679 on its way to the Niagara River from Green Bay, Wisconsin and it stayed hidden in Lake Michigan until just two years ago.

Here is a video,

http://www.aol.com/article/2014/12/24/divers-say-they-ve-found-holy-grail-of-shipwrecks/21120863/

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Picture of St. George submitted by Jerry R.

Jerry R. sent this picture and said the picture on yesterday's pendant is St. George slaying the dragon.  I'd say that is right.  Thanks Jerry!

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On the Treasure Coast the surf is still calm.  Tomorrow it is suppose to bump up to around five feet or so, however I'm not see anything but East and South winds predicted, so don't expect much out of that.

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Please remember to respond to the blog poll if you haven't already.  

Happy hunting,
TreasureGuide@Comcast.net

12/26/14 Report - Heavy Gold Pendant. Gold Investing. Archimedes Principle For Calculating Density To Help Identify Metals.

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



Half Ounce 14K Gold Pendant.

I hope you had a good Christmas. My hope is to try to make every day special in some way.  I know I'll falter from time to time but with determination might actually do a little better than in the past.

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The medallion in this picture is heavy.  It measures exactly .5 troy ounces.

It appears to be a sailing ship depicted on this side.

I didn't find any karat stamp on it, which is unusual for modern gold items, but it acid tests to 14K.







Below is a picture of the other side.

Looks to me like a guy on a horse spearing a dragon.

In front of the horse it looks like the piece has a signature.  At first to me it looked like it said MONET, but when I took a closer look, probably not.




I took a closer photo of what appears to be the signature. See the closeup photo of the signature below. 

What do you think it says?

Maybe MONS_.   The last character seems jammed in and is hard to make out.








Also also below is a picture of the edge showing how thick the pendant is and how high-relief the image is on the pendant.

Signature Right Side Up - I think.

Well, if you can figure out the signature, let me know. 


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If you find or buy gold coins or bullion for investing, you might wonder which would appreciate more.  That is what one fellow asked. You might benefit from the response found on the following web site.


http://coins.about.com/od/goldrarecoininvesting/f/gold_investing.htm?utm_term=spot%20gold%20today&utm_content=p1-main-5-title&utm_medium=sem&utm_source=msn&utm_campaign=adid-d5c9c919-b020-47b8-9f59-4375610b4f1d-0-ab_msb_ocode-5990&ad=semD&an=msn_s&am=broad&q=spot%20gold%20today&dqi=&o=5990&l=sem&qsrc=999&askid=d5c9c919-b020-47b8-9f59-4375610b4f1d-0-ab_msb


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Here is the mystery object found by Robert H. on a scale.  It weighs 35.7 grams.

Archimedes principle could be used to calculate the density of the object.

That is too much for me to deal with early in the morning on the day after Christmas though.

Maybe some other time.

There are tables that give the density of common metals.  I posted a good table like that one time.

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Don't forget to respond to the blog poll.

The surf on the Treasure Coast will be one or two feet until late Saturday when it will increase.

Happy hunting,
TreasureGuide@Comcast.net

9/2/20 Report - How Objects Sink in Beach Sand, Density of Common Metals. Movement of Sand. Tropical Storm Dolly

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



Gold Ring and Quarter In Cup of Sand and Water.

I always read  about how "heavy" objects sink in beach sand.  I understand why people say that, but it is not correct.

To the left you see a cup of genuine Treasure Coast beach sand and tap water.  I poured about half a cup of water into the cup and then about a half a cup of sand.  The sand filled the cup up over three fourths of the way with about a half inch of water on top of the surface of the sand.  I then put a quarter and thin gold ring on the sand.

How much do you think the quarter and ring sank in the last week?

Here is the answer.  Not at all!  

The way some people talk, or write, it sounds like gravity pulls objects like these right down through sand.  That didn't happen in this cup. 

You might say that this is a poor experiment, and it is nothing like a beach where the water and sand move.  Precisely!  It is not like a beach.  Everything is stable, and gravity alone will not pull coins or a rings like these down through this sand.  Other forces are at work when an object settles down to lower layers of sand on the beach.

On a beach the water and sand moves, and the moving sand covers  objects like these that do not move as much as sand.  But that is just part of it.

The objects will move some too, but much more often it is the sand that does MOST of the moving.

Before I go on I want to address another part of this.  People say that "heavy" objects sink, but it is not the weight of the object alone that determines if an object will find its way to lower levels of sand.  As I've explained in the past, a one-ton block of Styrofoam weighs one ton but will float in water and will not sink into the sand.  It is not the weight, but the density that has more to do with it.  But it isn't just the density of the object either that determines how an object will sink in the sand.  The shape of the object will have something to do with it too.

Lets focus on density for a bit.  The site linked through the following link presents a list of common metals along with their density.

http://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html

Here are some of the most relevant metals listed on that web site.  (Density is given 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

This correlates somewhat with how things will be distributed on a beach - but not perfectly

Aluminum is the least dense of the above group followed by titanium.  You'll see those often during poor beach conditions.

Copper and zine are sort of in the middle, with zinc being slightly less dense than copper.  Zinc cents will be found more towards the outer boundaries of coin holes, and copper cents just a bit closer to the center.

Lead is slightly more dense than silver.

The most dense of those listed above are platinum followed by tungsten, followed by gold.

(You might remember the tungsten ring that I found not long ago.  I caught it in the right light yesterday and saw on the inside of the ring that it was marked as tungsten.  On a detector the target ID came up as nickel.  I could tell when I picked it up that it was heavy for its mass, although without really thinking, I called it titanium at first before being corrected.)

If you look at that list, you'll have some indication of how those objects will sink into sand.  But as I showed above using the cup, they won't sink by themselves unless there are other forces at work.

The water moving the sand is a very big part of it.  I've explained before about trigger points.  Different objects require different amounts of water force to move them.  Grains of sand move relatively easily.  They have lower trigger points.  It takes less water force to move sand.  Objects like the coin and ring require more force to get them moving.  They have a higher trigger point.

When the water isn't moving much, the sand will be moved while the object remains relatively stationary.  Sand will be washed over the object, out from around the object, and if the shape is right, even from under the object.  This movement of sand is one of the biggest factors in determining how a object will sink into the sand.  With stationary sand, there is little to no sinking.

The shape of the object is also important in determining how an object will be moved on a beach.

I once showed an experiment in which lead sinkers having different shapes but the same weight were moved by crashing water - a disk shaped sinker was moved less by the same water than a egg shaped sinker, which was moved more than one of those fish shaped sinkers.  That is exactly what I predicted before the experiment.

The disc shaped sinker provided less surface for horizontally moving water to push against.  It hugged the surface of the sand something like a coin would.

Flat thin sheets are moved more by water - much more so than most other shapes.  As a result, even though copper is about three times as dense as aluminum, you will find thin copper sheets being deposited on a beach very much like aluminum.

Again, shape has a lot to do with how an object will sink in beach sand or be moved around and deposited.

For a more complete discussion of trigger points and the lead sinker experiment see my 3/10/14 post.
http://treasurebeachesreport.blogspot.com/2014/03/31014-report-experiments-on-movement-of.html

I also once showed an experiment that showed how an object "stepped" down a sand slope when the water current was rushing up the slope.  What happened is that the current moved the sand from around the object and from in front of the object as the object sat on the slope, and when enough sand was removed from the lower side of the object, the object slipped down the slope into the void, where it came to rest until the current moved enough sand for it to slip down another step.  Again, it was more about the sand being moved than the object sinking through the sand.

Of course loosely packed sand will move more easily and permit objects to "sink" lower more quickly than would packed sand.  That affects how much the sand moves too.  I can't get into all of the factors here, but wanted to make it perfectly clear that objects do not sink into sand simply by the force of gravity pulling the object down through the sand.

This might not seem important, but to me it is very important to me because it helps me understand how different types of objects will move on a beach, and therefore, where they are most likely to be found.  Sometimes when an object seems to be sinking, it is actually being covered rather than sinking.   And, of course, there are times when the water force is enough that more dense objects are moved forcefully by the water.  Coins have been observed to flip up and over a sand berm, for example.

That's all of that for today.


On the Treasure Coast we're supposed to have a one to two foot surf for a week or so.

There is a new tropical storm Dolly, but she will be hitting Texas.

Happy hunting,
TreasureGuide@comcast.net
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