Salt mines in particular are of the safest kind in the whole world, they are super stable. It's a self supporting rock with enough plasticity that the whole thing doesn't crumble down.
If you ever have privileged info of a huge earthquake happening, going into a salt mine is probably not the worst idea.
Plus it rehabilitates your lungs to be in a salt mine for a long time.
The only earthquake that happened in the region I am living during my lifetime was caused by a collapsing salt mine, though. (Small magnitude. I only heard about it because I was working at a particle accelerator lab at the time and the machine crew observed some beam instability caused by the ground vibrations, so they talked about it.)
What happens when they run out of salt? All the salt they put on the roads must end up back in the lakes but not in a way that is as easy to extract, right?
When that one mine runs out of salt? It will be closed. We as a humanity will not run out of salt, some places have the opposite problem: https://en.wikipedia.org/wiki/Monte_Kali
"According to the Werra Potash Mining Museum in Heringen, Monte Kali has been in operation since 1976; as of August 2016, it covered 98 hectares (240 acres) and contained approximately 201 million tonnes of salt, with another 900 tonnes being added every hour and 7.2 million tonnes a year."
Out of many worries about this world and its future, running out of salt is really at the bottom of the list.
You can always extract it form the sea by mere evaporation like our ancestors did. Plus salt deposits in the ground all over the world are massive, we had salty seas for billions of years.
https://www.youtube.com/watch?v=PcWRO2pyLA8
https://www.youtube.com/watch?v=CmHpNTYYWcM
https://www.youtube.com/watch?v=p_iZr2-Coqc
But then I wondered if modern mining engineering is a solved problem? In that they mostly know how to make safe tunnels?
Then I looked up how deep Erie is and it’s pretty shallow, with an average depth of 62 ft!
If you ever have privileged info of a huge earthquake happening, going into a salt mine is probably not the worst idea.
Plus it rehabilitates your lungs to be in a salt mine for a long time.
It what?
https://en.wikipedia.org/wiki/Halotherapy
https://en.wikipedia.org/wiki/Speleotherapy
"According to the Werra Potash Mining Museum in Heringen, Monte Kali has been in operation since 1976; as of August 2016, it covered 98 hectares (240 acres) and contained approximately 201 million tonnes of salt, with another 900 tonnes being added every hour and 7.2 million tonnes a year."
* https://www.riotinto.com/en/operations/anz/western-australia...
* https://australianminingreview.com.au/features/dampier-salt-...
You can always extract it form the sea by mere evaporation like our ancestors did. Plus salt deposits in the ground all over the world are massive, we had salty seas for billions of years.