The Atlantic Ocean opens
A rift becomes a sea, and the continents begin the journey to their present positions.
- When
- Known to
- ± 5 million years
- Era
- Jurassic, Mesozoic
Around 180 million years ago seafloor spreading begins in the central Atlantic between North America and northwest Africa, while a second rift opens between Africa and Antarctica. Gondwana starts to fragment in earnest. The Atlantic has been widening ever since at roughly the rate fingernails grow, and everything about modern ocean circulation and climate follows from its existence.