PLANET / EPISODE 01
Hundreds of miles beneath our feet, evidence locked inside minerals shows that parts of Earth’s mantle transition zone are hydrous — with minerals capable of storing water within their crystal structures.
WATCH THE EXPLORATION
The finished documentary will live here when it premieres. Until then, explore the evidence, research, and production notes behind the story below.
COMING SOON • PAST • PLANET • BEYOND™THE EXPLORATION
01DEEP EARTHEpisode 01 follows the evidence deep below the surface — from a tiny piece of ringwoodite to the mantle transition zone, where water can be stored inside the crystal structure of minerals under immense pressure.
This is not a buried ocean of open liquid water. It is something stranger: water stored within high-pressure minerals. How much water exists across the entire transition zone is still an active scientific question — and estimates vary by region and method.
FOLLOW THE EVIDENCE
Our source notes will live here alongside the episode so viewers can go beyond the documentary and examine the evidence themselves.
A ringwoodite inclusion preserved inside a diamond from Juína, Brazil provided direct evidence that the mantle transition zone is hydrous at least locally; analysis indicated the region it represented was hydrous to about 1% by weight.
READ THE RESEARCH ↗Electrical-conductivity studies have produced differing estimates. One study inferred roughly 0.1–0.2 wt% beneath the Pacific, while other work found that dry models can also fit conductivity observations.
COMPARE THE EVIDENCE ↗At roughly 410–660 km depth, high-pressure minerals such as wadsleyite and ringwoodite can store water in their crystal structures. Laboratory work shows their storage capacity can reach a few weight percent.
FOLLOW THE SOURCE ↗PRIMARY RESEARCH
Pearson et al. · Nature · 2014Hydrous mantle transition zone indicated by ringwoodite included within diamond ↗Huang, Xu & Karato · Nature · 2005Water content in the transition zone from electrical conductivity of wadsleyite and ringwoodite ↗Yoshino et al. · Nature · 2008Dry mantle transition zone inferred from the conductivity of wadsleyite and ringwoodite ↗Episode 01 is still in production. Additional citations and source notes will be added as the documentary is finalized.
KEEP EXPLORING
Follow the evidence deeper. Each path opens a different part of the story beneath our feet.
The mineral that carried a clue from hundreds of kilometers below Earth’s surface.
DEEPER EXPLORATION COMING SOONPut 410–660 kilometers beneath our feet into perspective — and see where this hidden reservoir can exist.
DEEPER EXPLORATION COMING SOONWhat the evidence says, what remains uncertain, and why “an ocean inside Earth” needs context.
DEEPER EXPLORATION COMING SOONEvery discovery opens another door.
VISUAL & PRODUCTION NOTE
Past • Planet • Beyond™ may use illustrations, animation, visual effects, recreations, archival or stock material, and AI-assisted or AI-generated media to help visualize subjects that cannot be directly photographed. Representational visuals are used for storytelling and are not presented as direct documentary footage when they are not.
READ OUR EDITORIAL & CONTENT DISCLAIMERTHE JOURNEY STARTS HERE
“THE CRAZY PART HAS TO BE TRUE™.”
Wonder gets our attention. Evidence earns the story.
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