Not a fact anymore

The deep-ocean floor is mostly flat and featureless.

What we know now

The seafloor contains enormous mountain ranges, deep trenches, volcanic ridges, seamounts, fracture zones, canyons, and broad abyssal plains.

Why it changed

Before systematic deep-sea sounding, the ocean bottom was largely unknown and was often imagined as a smooth basin. Nineteenth- and twentieth-century surveys revealed a rugged landscape, including the global mid-ocean ridge system.

Status
Overturned
Category
Ocean Science
Accepted for
≈205 years
Accepted approximately
Before the 19th century
Changed approximately
19th century–1950s
Bathymetric relief map of the Atlantic region. A long mid-ocean ridge runs down the center of the ocean basin, with broad abyssal plains, fracture zones, continental margins, trenches, and other large seafloor features visible around it.

Bathymetric relief of the Atlantic seafloor. The Mid-Atlantic Ridge runs through the center of the basin, surrounded by abyssal plains, fracture zones, seamounts, continental margins, and other large-scale relief. The deep ocean does contain broad flat plains, but they are only one part of a much more varied landscape.

NOAAWikimedia Commons: View source ↗Public domainConverted for web display

The abyssal plains really are broad and relatively level, but they are only part of the seafloor.

The old claim reflected a lack of measurements rather than strong direct evidence for smoothness.

Evidence

Sources and what they establish

Previous belief

Historical context

Related entries

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