Highlights
- Earth’s interior is cooling rapidly, scientists claim in new research
- Scientist said – Earth will become inactive like Mercury and Mars earlier than expected
- Heat flowing faster than expected, new experiment raised scientists’ concern
A study has found that the Earth’s interior is cooling faster than expected. This means that our Earth, like Mercury and Mars, will become inactive earlier than expected. Researchers led by ETH Zurich studied the thermal properties of the primary mineral bridgmanite. The team of researchers has developed a measurement system that measures the thermal conductivity of bridgmanite in the lab under the pressure and temperature conditions present inside the Earth.
This research has been published in the ‘Journal of Earth and Planetary Science Letters’. 4.5 billion years ago, the surface of the young Earth was extremely hot and was covered by a deep ocean of magma. Over millions of years, the Earth’s surface cooled and turned into a single surface. There is still no answer to the question of why the Earth cooled so rapidly and how long it may take for the above heat-driven processes to stop for cooling.
excessive heat being transferred
The possible answer may lie in the thermal conductivity of minerals that form a boundary between Earth’s core and mantle. This layer is important because the rock of Earth’s mantle is in direct contact with the hot iron-nickel melts of the outer core. The temperature transfer between the two layers is very high, so there is potentially a lot of heat flowing here. This boundary layer is mainly composed of the mineral bridgmanite.
A crystal of Bridgmanite is heated
However, researchers have not been able to estimate how much heat this mineral conducts from Earth’s core to the mantle. To overcome this difficulty, a team of scientists led by planetary scientist Motohiko Murakami of ETH Zurich in Switzerland illuminated a crystal of bridgmanite with a laser. Its temperature was increased to 2,440 Kelvin and pressure was increased to 80 gigapascals, which was similar to the conditions of the lower part of the Earth.
Earth may be colder than expected
‘This measurement system shows us that the thermal conductivity of bridgmanite is about 1.5 times higher than previously estimated,’ Murakami said. This means that the heat flow from the core to the mantle is greater than we thought. So the rate at which the Earth’s interior is cooling is greater than we thought. This process can also be accelerated because when it cools, bridgmanite turns into another mineral called post-perovskite, which is even more thermally conductive. This can increase the rate of heat loss from the core to the mantle.
.