# Geological studies of Earth’s internal water

> Live situation record from CLSTR: https://clstr.news/situations/geological-studies-of-earths-internal-water
> Updated: 2026-09-29T06:40:46.000Z. Sources: 6. Developments: 3.

Geological research has identified significant roles for water within the Earth’s interior layers. Initial findings from the Pilbara region of Western Australia suggest that surface water triggered massive volcanic eruptions approximately 3.1 billion years ago through ‘slab loss,’ a process where water-rich components from the outer crust sank into the mantle.

Subsequent research has identified a hidden water reservoir located approximately 3,000 kilometers beneath the surface, near the boundary between the mantle and the liquid outer core. Scientists utilizing seismic testing and laser-heated diamond anvil cells have investigated these deep structures, noting that such water is critical for Earth’s habitability and mantle movement.

Recent studies have refined the understanding of how water is stored at these extreme depths. Research suggests that water may exist nearly 2,900 kilometers below the surface, reaching the boundary of the Earth's core, though not in a liquid state. Instead, water is held within the crystalline structures of minerals.

By replicating the intense pressure and temperatures of the lower mantle using lasers and diamond anvil cells, researchers identified two new iron oxyhydroxide minerals, designated as Fe₅O₁₂Hₓ and Fe₇O₁₂Hₓ. These specific minerals are capable of binding hydrogen and remaining stable at the intense temperatures found near the core, where other water-bearing minerals typically lose stability.

## Timeline

### 2026-09-29: Earth's mantle may hold water 2,900 kilometers below the surface

Researchers have discovered new minerals that could store water deep within Earth's mantle, nearly 2,900 kilometers below the surface, potentially reaching the core boundary.

2 sources. https://clstr.news/cluster/earths-mantle-may-hold-water-2900-kilometers-below-the-surface

### 2026-09-15: Geologists discover hidden water reservoir 3,000km beneath Earth's surface

Geologists have discovered evidence of a massive water reservoir located 3,000 kilometers deep, near the boundary of Earth's mantle and outer core, which may influence tectonic activity.

2 sources. https://clstr.news/cluster/geologists-discover-hidden-water-reservoir-3000km-beneath-earths-surface

### 2026-09-13: Geologists find surface water triggered early Earth volcanic eruptions

Geologists have found that 3.1 billion years ago, surface water reached the mantle via ‘slab loss,’ triggering massive volcanic eruptions and proving the early Earth was a highly dynamic system.

2 sources. https://clstr.news/cluster/geologists-find-surface-water-triggered-early-earth-volcanic-eruptions

---
Cite as: Geological studies of Earth’s internal water. CLSTR, https://clstr.news/situations/geological-studies-of-earths-internal-water