Pacific Hemisphere losing heat faster than Africa, study finds

New research shows that the Pacific Hemisphere is losing heat much faster than the African Hemisphere.

This heat comes from Earth’s molten interior, which drives continental drift, CE Report quotes Kosova Press.

Landmasses trap more heat than ocean floors, indicating that the Pacific may have been significantly hotter in the past.

Scientists from the University of Oslo say that one side of Earth’s interior is cooling faster than the other—and the cause is ancient.

According to a study published in Geophysical Research Letters, computer models covering the past 400 million years were used to measure how “insulated” each hemisphere was by continental landmass—an important factor in retaining internal heat.

Earth’s hot, liquid inner core warms the planet from within. It also spins, generating gravity and Earth’s magnetic field, which protects the atmosphere.

Over extremely long periods, this interior will continue to cool until Earth becomes more like Mars, KosovaPress reports.

The surprising finding in the study is how unevenly the heat is distributed—but the reason is intuitive:
Parts of Earth are covered by more land, creating a kind of thermal blanket that traps heat.

This contrasts with how most of Earth’s heat actually escapes:

“The thermal evolution of Earth is mostly controlled by the rate of heat loss through the oceanic lithosphere,” the study states.

Why is this important?

Earth’s mantle acts like a convection oven. Every day, the ocean floor shifts slightly—new seafloor forms from magma at mid-ocean ridges, while old seafloor is destroyed beneath continents.

To study how Earth's heat behaves, scientists divided the planet into the Pacific and African hemispheres, then mapped Earth’s surface into a half-degree grid.

They combined earlier models of seafloor age and past continental positions over the last 400 million years, nearly doubling the timeframe of previous models, which only went back 230 million years.

They then calculated how much heat each cell of the grid retained over time and found that the Pacific side has cooled much faster.

Why?

The ocean floor is thinner than landmass, and the cool ocean water above it absorbs internal heat more efficiently.

Think of the giant Pacific Ocean compared to the land-heavy hemisphere of Africa, Europe, and Asia—it makes sense that more heat escapes from the largest ocean basin on Earth.

The Pacific Hemisphere has cooled about 50 Kelvin more than the African Hemisphere, which scientists attribute to the consistently faster plate movements in the Pacific over the last 400 million years—meaning it was once significantly hotter.