Solved cryptogram
The ocean averages several kilometers in depth, so the sea floor is mostly abyssal plain.
Earth Science Facts, sourced to NOAA.
What it means
People picture the ocean as the shallow, sunlit water they can swim in, and that band is a thin rim around the edge of the continents. The average depth is a little under four kilometers, and the great majority of the sea floor is flat, cold, dark plain lying far below the reach of sunlight. More than nine tenths of the ocean by volume has never seen a photon from the sun.
The claim comes from NOAA, and the page it comes from was read on 2026-08-27 to confirm it still says this.
This is not the kind of claim that goes out of date, which is why it was set as a puzzle rather than a fact with a shelf life.
Solve it yourself
This fact is a cryptogram here: 73 letters over 20 different ones, graded hard.
- SourceNOAA
- CollectionEarth Science Facts
- Difficultyhard
- Length73 letters, 20 of them different
Nearby in the collection
The facts either side of this one.
- Royal Society of Chemistrymedium, 72 letters
- NASAmedium, 76 letters
- NOAAmedium, 74 letters
- NOAAmedium, 74 letters
About as hard as this one
Scored closest to it by the model behind our guide to solving cryptograms.
- U.S. Geological Surveyhard, 78 letters
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- NASAmedium, 74 letters
- U.S. Geological Surveymedium, 78 letters