As you read this story, you will learn the following:
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Research shows that the Pacific hemisphere is losing heat faster than the African hemisphere.
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The heat comes from the molten interior of the Earth, causing the continents to drift.
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Land absorbs more heat than the ocean floor, suggesting that the Pacific Ocean was hotter in the past.
One side of the Earth’s interior is losing heat much faster than the other, and the culprit is actually as old as time, scientists at the University of Oslo say.
A study published in Geophysical Research Letters Computer models from the past 400 million years were used to calculate the extent to which each hemisphere was “insulated” by continental mass, a key quality that keeps heat inside rather than releasing it. This pattern can be traced back to Pangea.
The Earth has a hot liquid interior that warms the entire planet from the inside. It also rotates, creating gravity and the Earth’s magnetic field. This keeps our protective atmosphere close to the Earth’s surface.
In the long term, this interior will continue to cool until Earth becomes more like Mars. What’s surprising in the study is the uneven distribution of heat, but the reason makes intuitive sense: Parts of the Earth have been insulated by more land, creating some kind of thermos layer that traps heat.
This is in stark contrast to the way Earth loses most of its heat: “Earth’s thermal evolution is largely controlled by the rate of heat loss from the oceanic lithosphere,” the study authors wrote. Why is this the site that loses the most? To do this, we need a rapid and in-depth understanding of continental drift.
The mantle is like a convection oven that powers a treadmill. Every day, the seafloor’s surface shifts a little; new seafloor is born from magma erupting along the Continental Divide, while old seafloor is crushed and melted beneath existing continental land masses.
To study how heat behaves within the Earth’s interior, scientists built a model that divided the planet into an African and Pacific hemispheres, then divided the entire surface into a grid half a degree of latitude and longitude.
The scientists combined several previous models, such as the age of the seafloor and the location of the continents over the past 400 million years. The team then calculated how much heat each grid cell contained over its long lifetime. This paved the way for calculating the overall cooling rate, and the researchers found that the cooling rate was much faster on the Pacific side.
Cumulative mantle heat loss (ocean + continent) over the past 400 miles. The area above large low-shear velocity provinces in the Pacific and Africa is shown with blue and orange lines. The light dashed meridian represents the separation of the Pacific and African hemispheres. Carlson et al. etc./Geophysical Research Letters
The ocean floor is much thinner than the massive landmasses, and the temperature inside the Earth is “cooled” by the vast amounts of cold water above it. Think of the vast Pacific Ocean versus the continents of Africa, Europe, and Asia across the way. It makes sense that heat would dissipate faster from the world’s largest ocean floor.
Previous studies of this seafloor effect only went back to 230 million years ago, meaning the new model, which goes back 400 million years, almost doubles the time frame studied.
The findings are surprisingly contradictory. The Pacific hemisphere is about 50 Kelvin warmer than the African hemisphere, but “the plate velocities in the Pacific hemisphere have been consistently higher over the past 400 years.” [million years]”Recommends Pacific was Hotter at some point.
Was it covered by land at some point in the distant past, thus retaining more heat inside? There are other possible explanations, but regardless, high tectonic activity in the Pacific today suggests a thermal difference. The more the mantle melts, the more the plates can slide and crash together.
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