Mid-Atlantic Ridge: new crust beneath the ocean
The ocean widens between South America and Africa. At divergent boundaries, rising mantle partly melts and magma solidifies into new oceanic crust.
The ocean widens between South America and Africa. At divergent boundaries, rising mantle partly melts and magma solidifies into new oceanic crust.

Annual surface temperature from CESM (T): a model estimate, not a direct observation of the past.
0 Ma: pre-industrial climate/CO₂; modern sea-level and O₂ references.
Glacial-interglacial cycles with 120m+ sea level swings. Homo sapiens spread from Africa across the globe, and most megafauna went extinct.
Annual model means · 0 Ma: pre-industrial
Present