• Rodeo@lemmy.ca
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    1 year ago

    Why only 21 inches? Soil temps aren’t stable until like 6 feet down, and then it’s closer to 12 C.

    • Lazz45@sh.itjust.works
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      1 year ago

      That is the deepest depth I could find being actively tracked on the website I ended up on. I did not wanna do a deep dive into “great” average soil temp data lol. If you have a good source of data I will gladly change my comment to include the updated numbers. I wanted to say the average soil temperature at depth is ~50-55 degrees F, but I hopped online to make sure that was not a number that I know to be true due to where I live. Good to know that its roughly 6 feet where it stabilizes

      • Rodeo@lemmy.ca
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        1 year ago

        If you go down deep enough the earth temperature is stable at 12 C. But I’m pretty sure that’s like thousands of feet down. Geothermal rigs drill 500+ meters (1600 feet) down. Having a hard time finding a source on the stable earth temp though.

        I mentioned 6 feet because it’s well below the frost line where I am, but I guess in that part of Iran they probably don’t have to worry about that.

        Mostly I was just wondering if you had found something on how deep those waterways were actually built.

        • Lazz45@sh.itjust.works
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          1 year ago

          Yeah thats exactly the issue I ran into. I started googling stable soil temp to confirm what I thought, and rapidly ran into a lack of answers lol. Any data I could find for free on websites didn’t seem to go very deep.

          In terms of depth of the Qanats, yeah I was wondering the same. Without any modern tools I’m not sure how deep they would be willing to dig out (although I bet it’s easy digging in Iran, likely sand/dry dirt vs. clay and sopping wet boggy soil).

          I am at work but I’ll see if I can dredge up info on Qanat depth