Any paper on this specific initiative? This sounds like a slam dunk for any population center needing district heat.

Here's a website where they're putting up data from the borehole.

https://deepgeothermalheat.engineering.cornell.edu/research/

Note the wireline logs. You can see the radioactivity (which is where the heat comes from) go way up as they reach the crystalline basement rocks.

The technical issue that's going to determine if this is feasible is how quickly water from an injection well can get to a withdrawal well. This depends on the how fractured the rocks are.

Also: publications and presentations

https://deepgeothermalheat.engineering.cornell.edu/publicati...

Not the same project, but in Otaniemi they drilled 6km to find the project to not work as planned. Unfortunately this was the best article I could find for now: https://www-lansivayla-fi.translate.goog/paikalliset/4558850...

> In Finland, the temperature rises by 18 degrees per kilometer.

The geothermal gradient at Ithaca is a bit higher than that.

Also, correct me if I'm wrong, but isn't Finland mostly underlain at fairly shallow depth by hard crystalline rocks that are more expensive to drill through? At Ithaca, there's a 3 km thickness of sedimentary rocks before hitting that basement rock.

Grossly oversimplified, inland is swamps & lakes atop crystalline rocks, while Helsinki is landfill punctuated by granite outcroppings.

The caveat is that you will cool the hole extracting the heat, exhausting usable heat the sooner the more you extract. Whether the sustainable heat energy per unit of invested money is attractive depends on circumstances.