Pyhäsalmi mine is the biggest operational basemetalmine in Finland. It is also the deepest metal mine in Europe. The mine is owned by First Quantum minerals.
- depth 1450 m, ca 4000 metres water equivalent (m.w.e.)
- the average rock density varies between 2.81-2.83 g/cm3
- low radioactivity: U 0.8 ppm, Th 3.2 ppm, K 1.17%, Rn < 70 Bq/m3 (depends on ventilation)
- accessibility: a truck road (maximum load size 2.6 m x 2.8 m x 8 m) and a lift all the way down
- existing infrastructure including buildings, electricity, water pumping and air-conditioning
It provides space for scientific experiments:
- a laboratory and an office on the surface
- currently active underground research rooms at 90m, 210m, 400m, 660m and 970m
- new caverns in the new mine (1440 m) can be built if needed
The rock overburden provides a natural shielding against cosmic ray muons. The flat surface reduces the muon flux from non-vertical directions. The muon flux at the lowest levels is less than 10-4 1/m2s.
This site provides the following advantages:
- Northern location: Magnetic field vertical, cosmic ray flux slightly higher, earth matter effect smaller for solar neutrinos, provides opportunities for better positioning of a supernova, compared with other sites most of which are at the same latitude
- Environmental safety
- Local authorities very favorable