Seismic data suggests vast reserves of water locked in rock hundreds of kilometres down.
The finding, if confirmed, would reshape our understanding of where Earth's water came from — and how much remains hidden.
The water is not liquid but chemically bound within minerals under immense pressure.
Water, all the way down
It is a reminder of how little we know about the planet beneath our feet.
"The deep Earth is the least explored place we know."
Analysts point to a handful of forces driving the story forward:
- Signatures detected in seismic waves
- Water bound within dense minerals
- Implications for the planet's history
Confirming the reservoir will take years of careful modelling.