Earthquake Physics

Understanding how earthquakes begin and evolve remains one of the biggest challenges in Earth sciences. At the BedrettoLab, researchers address this by working directly next to a natural fault in one of the world’s first On‑Fault Observatories. Here, controlled experiments and dense instrumentation allow scientists to observe fault activation and small earthquakes under realistic underground conditions, offering unprecedented insights into the physics of earthquakes.

Despite major progress over recent decades, it is still impossible to predict exactly when and where the next earthquake will strike. Advancing this understanding requires direct, high‑resolution observations of fault behaviour, which is rarely achievable in natural settings.

The BedrettoLab’s Earthquake Physics Testbed makes this possible. A newly excavated 120‑meter tunnel (constructed between 2023 and 2025) and a dedicated cavern provide direct access to a natural fault zone at more than one kilometre depth. From here, researchers have drilled boreholes that intersect or closely approach the fault, enabling controlled water injections and detailed on‑fault monitoring through a dense network of sensors. These sensors capture seismic waves and measure deformation, pressure changes, temperature, and flow rates with high precision. This setup forms the foundation of the On‑Fault Observatory.

Within this controlled environment, scientists can reactivate the fault by injecting water under carefully designed conditions, generating thousands of tiny earthquakes. Although these events are far too small to be felt, they produce an exceptionally rich dataset. This enables researchers to investigate the full sequence of earthquake processes: fault activation, nucleation, and rupture propagation. The flexible monitoring and injection infrastructure supports multiple hypothesis‑driven experiments across different patches of the fault over the coming years.

The insights gained from this work deepen our fundamental understanding of earthquake physics and support the safe development of geo‑energy technologies. In the long term, this research may also contribute to improving earthquake forecasting by revealing how faults behave at depth under controlled, repeatable conditions.