Nuclear tests at Mt. Mantap have reactivated intraplate faults.

Intraplate faults at Mt. Mantap have been reactivated for years after nuclear tests, with seismicity increasing and fault activity becoming spatially organized.

• Why it matters: Understanding long-term fault reactivation is crucial for assessing seismic risks associated with underground nuclear testing and the stability of the crust in test regions.
• What they did: Analysis of 17 years of waveform data revealed a steady rise in seismic activity and delayed fault reactivation, with earthquakes clustering beneath asymmetric topography, indicating stress redistribution.
• The result: These findings demonstrate that nuclear tests can cause multiyear fault reactivation under certain geological conditions, extending seismic activity well beyond immediate posttest periods.