7/14/21 Report - Coins Found On Bank of River. More Coastal Flooding Coming. Library Presents Treasure Hunting Talk.

 Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.

When amateur treasure hunters discovered 107 ancient Roman coins on the banks of a river in the Netherlands at the end of 2017, they had no idea why the coins were there. Now archaeologists have cracked the case.

In Roman times, there was likely a shallow crossing known as a ford at this narrow part of the river, and superstitious travelers probably offered up coins to guarantee safe passage across the waterway, like a wisher throwing a penny into a fountain, archaeologists wrote in a report released June 6 by the Cultural Heritage Agency of the Netherlands...

Here is the link for more about that.

100 Roman coins were likely an offering for safe passage across river | Live Science

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A NASA  report is predicting higher tides and more flooding in the 2030s.

... While the study highlights the dire situation facing coastal cities, the lunar wobble is actually a natural occurrence, first reported in 1728. The moon's orbit is responsible for periods of both higher and lower tides about every 18.6 years, and they aren't dangerous in their own right.

"In half of the Moon's 18.6-year cycle, Earth's regular daily tides are suppressed: High tides are lower than normal, and low tides are higher than normal," NASA explains. "In the other half of the cycle, tides are amplified: High tides get higher, and low tides get lower. Global sea-level rise pushes high tides in only one direction – higher. So half of the 18.6-year lunar cycle counteracts the effect of sea-level rise on high tides, and the other half increases the effect."...

Here is that link.

NASA predicts a "wobble" in the moon's orbit may lead to record flooding on Earth - CBS News

So if you can wait, you might have more dune erosion and better hunting in the 2030s.  The moon "wobble" might also correlate to some extent with periods of greater and lesser beach finds.

Thanks to Dan B. for that link.

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I've done a number of posts on decision theory and signal detection theory.  Both are well developed and supported by a lot of data.  They apply to human behavior in a variety of circumstances including metal detecting.  

Here is a link to one of my previous discussions on the subject.

Treasure Beaches Report Part 2. 2020 and Beyond: 8/8/20 Report - Intro To Signal Detection Theory for Detectorists and Treasure Hunters. One Huge Meg Tooth. (tbr2020.blogspot.com)

And here is an illustration from that post that expresses a simple idea, but one that you might find useful if you keep it in mind.

The diagram shows that there are two ways to be correct and two types of error.  

Finding a decision rule that results in optimal performance involves finding a balance, and it involves a several factors.  I'm going to try to present that in a clear manner in the near future, but it is taking some time to translate it into regular language and eliminate all the complicated math. 

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Alberto S. sent me the following notice of Jim Wilson's upcoming talk on treasure hunting.  Contact information for more details can be found at the bottom of the notice.

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You might be interested to know that when you take a DNA test and submit your sample to a company for analysis, some, if not all, of those companies send the sample to China to be analyzed.  China sends back the results, but keeps a copy of the data.  They are building a database of human DNA, but it is illegal for the Chinese population to share their DNA information with other countries.  Wonder why that is?  

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The surf will be up a touch today, but the swells are out of the east.  The tides are moderate.

Source: MagicSeaWeed.com.

Happy hunting,

Treasureguide@comcast.net