A slide deck

How does life change as you descend through the ocean's five zones?

A descent through the ocean's five zones — sunlight, twilight, midnight, abyss, and hadal — tracing how light, temperature, pressure, and life change on the way down.

Mojulo · July 7, 2026

Into the Deep

A descent through the ocean's five zones — from the sunlit surface to the crushing dark of the trenches.

slide 1Title
200 m1,000 m 4,000 m6,000 m11,000 m SUNLIGHT ZONE 0–200 m · warm, lit, most life TWILIGHT ZONE 200–1,000 m · the last blue glow MIDNIGHT ZONE 1,000–4,000 m · no sun, ever THE ABYSS 4,000–6,000 m · near freezing HADAL ZONE 6,000–11,000 m · trenches
slide 2Ocean cross-section
1 · The Sunlight Zone 0 – 200 m · the ocean's bright skin Lightfull daylight — enough for photosynthesis Tempwarm, and shifting with the seasons Life~90% of all marine species LIGHT REACHING THIS DEPTH full surface intensity 400nm500600700nm the whole spectrum arrives — blue-green strongest
slide 3Sunlight Zone
2 · The Twilight Zone 200 – 1,000 m · the last blue glow Lighta faint blue haze — too little to grow anything Lifelanternfish, hatchetfish, krill, squid Notebillions migrate up to feed each night LIGHT REACHING THIS DEPTH full surface intensity 400nm500600700nm only a faint blue-green survives; red is long gone
slide 4Twilight Zone
76% make light Most of the deep makes its own light In the twilight and midnight zones, roughly three in four animals are bioluminescent — they glow to hunt, to hide, and to find one another.
slide 5Most of the deep makes its own light
3 · The Midnight Zone 1,000 – 4,000 m · perpetual dark Lightnone from the sun, ever Tempa steady 4 °C Lifeanglerfish, gulper eel, vampire squid LIGHT REACHING THIS DEPTH full surface intensity No sunlight — the only light is life's own 400nm500600700nm
slide 6Midnight Zone
4 · The Abyss 4,000 – 6,000 m · the abyssal plain Temp2 – 3 °C, unchanging Coverabout three-quarters of the deep seafloor Lifesea cucumbers, brittle stars, tripod fish LIGHT REACHING THIS DEPTH full surface intensity No sunlight — darkness, unbroken 400nm500600700nm
slide 7The Abyss
5 · The Hadal Zone 6,000 – 11,000 m · ocean trenches Pressover 1,000 atmospheres at the floor Lifesnailfish, pale amphipods, chemical microbes Namedfor Hades — the deepest trenches on Earth LIGHT REACHING THIS DEPTH full surface intensity No sunlight — the deepest dark on Earth 400nm500600700nm
slide 8The Hadal Zone
Drop Everest into the trench — it still won't reach the bottom sea level · 0 m 5,000 m 10,000 m Mt Everest 8,849 m tall Mariana Trench floor · 10,935 m ~2,086 m of ocean still below the summit
slide 9Everest in the trench

The dark majority

The deep sea is the largest living space on Earth — and the least explored. We have better maps of Mars than of our own ocean floor. Most of what lives down there, we have never seen.

slide 10The dark majority