Qualla: Centre for Underground Physics in Pyhäsalmi

Centre for Underground Physics in Pyhäsalmi: Introduction

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Tiia Monto, CC BY-SA 3.0. To study what comes from the sky, sometimes you have to go underground. Nearly a mile beneath the forests of central Finland, inside Europe's deepest base metal mine, physicists operate sensitive detectors in near-perfect silence. The Centre for Underground Physics in Pyhäsalmi, known as CUPP, occupies tunnels within the Pyhäsalmi Mine at depths reaching 1,430 meters. At that depth, the rock overhead absorbs the background radiation that blinds surface-level particle detectors, turning a zinc and copper mine into one of the quietest laboratories on Earth.

Image: Tiia Monto | CC BY-SA 3.0

Centre for Underground Physics in Pyhäsalmi: Why Physicists Go Underground

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Tiia Monto, CC BY-SA 3.0. Particle physics has a noise problem. Cosmic rays bombard Earth's surface constantly, flooding detectors with a blizzard of particles that obscure the faint signals scientists actually want to measure. The solution is elegantly simple: put your instruments under enough rock to fi...

Image: Tiia Monto | CC BY-SA 3.0

Centre for Underground Physics in Pyhäsalmi: Catching Cosmic Whispers

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Tiia Monto, CC BY-SA 3.0. The laboratory's flagship project is EMMA, the Experiment with MultiMuon Array. A collaboration between the universities of Oulu, Jyväskylä, and Aarhus, along with the Russian Academy of Sciences, EMMA studies the composition of cosmic rays at energies above one petaelectronvolt,...

Image: Tiia Monto | CC BY-SA 3.0

Centre for Underground Physics in Pyhäsalmi: Carbon-14 in the Dark

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Tiia Monto, CC BY-SA 3.0. At 1,430 meters depth, another experiment probes a different mystery. The C14 experiment, a collaboration between Finnish universities and the Russian Academy of Sciences, measures the radioactive purity of scintillator liquids used in particle detectors worldwide. These hydrocar...

Image: Tiia Monto | CC BY-SA 3.0

Centre for Underground Physics in Pyhäsalmi: A Mine Becomes a Window on the Universe

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Tiia Monto, CC BY-SA 3.0. CUPP was once a candidate site for LAGUNA, a proposed European neutrino observatory that would have been one of the largest underground physics facilities ever built. The project ultimately lost momentum as the global neutrino research community shifted focus toward the American ...

Image: Tiia Monto | CC BY-SA 3.0