News: Thunderstorms can generate seismic waves (“thunderquakes”), which + fibre-optic cables + DAS can map the shallow subsurface without drilling.

About

• Thunderquakes: Lightning → rapid air heating → shock wave → energy reaches ground → seismic waves.
• DAS: Fibre-optic cable → thousands of vibration sensors.
• Study: 4+ km cable + 2,100+ sensors → 458 thunderquakes recorded over 2 years.
• Rayleigh waves: Travel along surface → provide subsurface information.
• Seismic dispersion: Different frequencies → different speeds/depths → estimate subsurface properties.
• Depth: Imaging possible up to ~100 m without drilling.

Applications

• Groundwater → movement detection
• Geohazards → sinkholes + underground voids
• Geology → fractured/weathered rocks
• Environment → contamination monitoring
• Infrastructure → site + foundation assessment

Karst Landscapes

• Soluble rocks (limestone + dolomite) + groundwater dissolution → caves + fractures + sinkholes.
• Cover ~20% of global continental land + affect ~25% of world population.