Monday, July 27, 2015

7/27/15 Report - MILLION DOLLARS Of Treasure Recently Found On A Treasure Coast Shipwreck Site. The Difference Between Compact And Mushy Sand.


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


2015 Gold 1715 Fleet Discoveries
Photo source : FloridaToday.com link below





















For a few weeks, the Schmitt family and 1715 Fleet — Queens Jewels LLC had a million-dollar secret on their hands. Last month, they recovered $1 million worth of sunken Spanish jewels off the Florida Coast.
“The treasure was actually found a month ago,” said Brent Brisben of 1715 Fleet — Queens Jewels LLC. Keeping the news under wraps was “particularly hard for the family that found it. They’ve been beside themselves.”
Recovered:
  • 51 gold coins
  • 40 feet of ornate gold chain
  • A single coin called a Royal made for the king of Spain, Phillip V, a news release states. Only a few are known to exist, and the coin — nicknamed “Tricentennial Royal” — is dated 1715. Brisben said the extremely rare silver-dollar-sized coin is worth “probably around half a million dollars itself...
Here is the link for the rest of the story and a video.

http://www.floridatoday.com/story/news/local/2015/07/27/family-finds-sunken-spanish-treasure/30744269/


Take a look at that Gold Royal in the middle of the photo.  You can also see part of the chain to the left.

Thanks to Jorge and Doug for sending me this link.

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People that are passionate about certain activities learn a lot about those activities.   They put knowledge together that draws from different fields of study and may even add new knowledge.

I've been talking a lot about how sand and other objects move on a beach and in the water. I feel like I've learned a lot in the last few years and have been drawing from a variety of scientific disciplines but also from people who are very passionate about different recreational activities.  Some of what I've learned lately, I've learned from surfers.  I've shown Scott Little's photography, for example. Obviously, surfers are interested in waves and may know more about waves in some ways than oceanographers.  Today I learned something from another recreational group -  those who do sand sculpture.

You've probably stepped onto a beach and you sank in up to your ankles.  Another time you might have stepped out on the same beach and it felt like pavement.

We talk all the time about mushy sand, which is a very poor sign for beach detectorists.  Mushy sand is often composed of larger grains,  Fine grain sand obviously settles more, but that is not all there is to it.

Here is what the sand sculpture web site says.
In a word the big secret is "friction". More specifically, the sum total of all friction between the grains acting on each other. This is why compaction is so important. When you compact sand you increase the friction between the grains.

Uncompacted sand has relatively large pore spaces between the grains but compacted sand shrinks these spaces increasing points of contact between the individual grains and thereby increasing the friction between them. The more friction there is, the more resistant the grains are to separation.

One other important dynamic is "cross-linking", a term from soils engineering. Forcing randomly shaped grains tightly together causes many of them to naturally cross-link. Cross-linking is a common technique in masonry work where vertical joints between bricks, stones and block joints are intentionally staggered thereby vastly increasing the strength of the structure.

Friction is also why certain sands are better than others. Finer sands will naturally have smaller pore spaces and angular grains are most likely to tightly interlock and cross-link. Rounded grains will always have larger pore spaces between grains no matter how well compacted, and a naturally smooth surface further reduces friction. Beyond being merely rounded as the individual grains become more spherically shaped the grains also become incapable of cross-linking. Try to imagine stacking a pile of bowling balls. The advantages of a sand that compacts well are easy to see and will always make for a more enjoyable day when sculpting. 

Here are three illustrations from the same source.

To compact sand before sculpting they build a formwork (box) and fill the box with six inches of wet sand, then compact the six inch layer with a construction compactor. Then they add an additional six inch layer of wet sand on top of the compacted layer and compact the new layer, repeating until they have enough to begin the sculpture.

Here is the source link.

http://www.sandscapes.com/how_to/images/particle4c.gif

If you generalize from the above, you'll understand some of the differences between mushy and compact beach sand.

There is more to it, I'm sure.  I didn't take into account exactly how the sand was deposited.  Often it will be in layers as wet sand is deposited when the tide is up.

When you have compacted sand, it will take more to get it into suspension and moving.

I pay attention to the feel of the sand beneath my feet when detecting.  If I am walking along and feel the sand under my feet become compact, I would be sure to check that area for any good targets.

There is a lot more that I didn't get into, but that is as far as I want to take this today.  I got a late start.

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The surf on the Treasure Coast will be very smooth the next couple of days.

Happy hunting,
TreasureGuide@comcast.net