Century-old stone “tsunami stones” dot Japan's coastline (2015) (opens in new tab)

>Onagawa was… 60 kilometers closer than Fukushima Daiichi [to the epicenter] and the difference in seismic intensity at the two plants was negligible. Furthermore, the tsunami was bigger at Onagawa, reaching a height of 14.3 meters, compared with 13.1 meters at Fukushima Daiichi. The difference in outcomes at the two plants reveals the root cause of Fukushima Daiichi’s failures: the utility’s corporate “safety culture.”

>Before beginning construction, Tohoku Electric conducted surveys and simulations aimed at predicting tsunami levels. The initial predictions showed that tsunamis in the region historically had an average height of about 3 meters. Based on that, the company constructed its plant at 14.7 meters above sea level, almost five times that height.

>Tepco, on the other hand, to make it easier to transport equipment and to save construction costs, in 1967 removed 25 meters from the 35-meter natural seawall of the Daiichi plant site and built the reactor buildings at a much lower elevation of 10 meters.

https://thebulletin.org/2014/03/onagawa-the-japanese-nuclear...

The reactors were also largely fine except for grid connections and the hurricane-resistant backup generator in the basement. It was told ad nauseum at the time that there could have been couples of those on the roofs and the reactor could have just survived.

"Beyond" is completely ambiguous in this case. Do you mean above or below?

Do you have a citation for this? The most Gemini could say is: "While research has not identified a specific tsunami stone located at the Fukushima Daiichi site that was directly violated, the spirit of these ancient warnings was undeniably ignored." (https://aistudio.google.com/app/prompts?state=%7B%22ids%22:%...)

That suggests a possibly better strategy (though very long term): pepper the portion of the landscape believed to be safe with "it is safe to build here" monoliths, each as stable as a typical building, and over time only the ones that speak truly will remain.

Would work for volcanoes and earthquakes as well.

Can't wait for round 2!

It’s almost as if these stories come in waves.

I might have submitted it before already :)

or its just a new round of 10,000 who are learning about this for the first time, just like you once were

https://xkcd.com/1053/

Depends on how metaphorical and/or political you want to get.

Arguably books could be considered warning waystones, but that's a stretch in this context.

Physical monuments though, we have loads, lots of war memorials are/were intended as warning about the cost of war.

Auschwitz-Birkenau being left as as it is could be considered another.

If you want to get really close to similar intentions there are the long term nuclear waste warnings:

https://en.wikipedia.org/wiki/Long-term_nuclear_waste_warnin...

A bit more esoteric (and less warningy) and you get the signals we send in to space intentionally as a time-capsule/marker for potential alien contact.

I think the obvious answer in the modern world would not be a phsyical one, but some sort of measure of wealth inequality. At some point, if too few have too much it destroys a country from the inside out over the long run. It does far more damage than any tsunami ever could. I don't have a number or exact measure in mind, but that would be the warning I would leave to future generations.

With radiation half lives what they are, our society should be brainstorming how to segregate and mark nuclear waste storage areas. All areas that store radioactive waste.

Without clear warnings and boundaries humanity is just waiting for a catastrophe.

A tiny sign and words don’t count.

You can put warnings everytime there is a tsunami, which is "often" in Japan, but the issue is that a massive one like the 2011 earthquake and tsunami is a once in a millenium event so would indeed need to rely on very old warnings:

"The 2011 Tōhoku earthquake occurred in exactly the same area as the 869 earthquake, fulfilling the earlier prediction and causing major flooding in the Sendai area. [1]

Modern society is not good at this sort of very long term consideration and planning.

[1] https://en.wikipedia.org/wiki/869_J%C5%8Dgan_earthquake

Oldest known stones date back to the early 1400s but there must have been older stones. Already those stones are mostly unreadable because of erosion and they are dated by secondary sources.