The title says it all:
One side of Earth’s interior is losing heat much faster than the other
This article from NewScientist (20 March 2021) explains:
Our planet is a bit lopsided. One half of Earth is losing heat from the planet’s interior faster than the other, and has been for much of the past 400 million years.
The uneven heat loss is probably a relic of past supercontinents, when all the land masses were joined together on one side of the planet.
“We see that the Pacific has lost more heat,” says Krister Karlsen at the University of Oslo in Norway. “That is in large part due to the distribution of the continental land masses.”
Why?
The first [dataset] concerns the amount of heat from Earth’s interior that flows up through the crust. This data set shows that oceans aren’t as good at trapping heat inside Earth as the continents are, says Karlsen. That is partly down to the thickness of the rock: continental crust is often many kilometres thicker than oceanic crust, so it is a better insulator.
The second data set relates to the movement of the continents deep in prehistory. Some continental rocks carry telltale traces of Earth’s magnetic field, which varies around the globe.
Data from these rocks can be used to show that Earth has, on several occasions, been home to a supercontinent – and it can help establish some of those supercontinents’ approximate position. The most recent supercontinent was Pangaea, which existed from around 335 to 175 million years ago, and was centred roughly where Africa lies today.
Which leaves me to wonder: is the imbalance enough to impact Earth’s orbital dynamics around the Sun?
