Scientists Discover Early Subduction Events Triggered by Theia Collision, Changing Earth’s History

Jakarta –

Scientists have found evidence that subduction events, which drive plate tectonics, occurred early in the Earth’s formation, and this contradicts existing models. To explain how this happened, planetary scientists point to a bump that was triggered by the collision between Earth and Theia, a Mars-sized object that formed the moon.

Earth is the only planet with plate tectonics, and without the continents, we wouldn’t be here, and there wouldn’t be any other species. As a result, the possibility of very rare plate tectonics is being considered as one of the possible explanations for the Fermi Paradox.

The idea that tectonic plates on Earth are related to the Moon has been put forward many times, with different interpretations of the relationship. Most of these claims have little evidence, but 4.3 billion year old crystals from Western Australia may be missing.

The crystal is zircon, a type of rock prized by geologists for its stability and internal clock. Zircon does not allow lead to pass through when it is formed, but uranium and thorium do. This decomposition leads to a well-understood record, so that the ratios of the elements within it indicate the age of the zircon.

For more than 20 years, some scientists have argued that the chemical properties of some very old zircons indicate that they were produced during subduction events, when tectonic plates push or pulling other tectonic plates into the mantle.

However, plate tectonics today is driven in part by solid oceanic debris entering the mantle, which should have occurred early in Earth’s existence. A research team has now provided an explanation. Their modeling shows that when Theia hit Earth 4.51 billion years ago, the resulting heat would have continued for a long time, raising the temperature of the mantle boundary long after the magma ocean that caused the impact to be solidified.

The extra heat at the core comes not only from the energy that could be given off by the collision, but also from the decay of radioactive elements with a long half-life. carried by Theia. This would then produce a strong plume condition, with large balls of heat rising from the boundary, weakening the Earth’s crust and upper mantle. In different scenarios, the models used by the study authors consistently show that, around 120 million years after the impact, a superheated plume of mantle would have approached the surface and started removed.

The study, published in the journal Geophysical Research Letters, says that changing certain assumptions will change the timeline, but as long as the temperature is higher than 3,773 K at the base boundary for a long time, and that the pressure near the surface. it is not too big, then a sub-transition will come.

“The large impact was not only the reason for the formation of our moon, if so, it also determined the early conditions of our Earth,” said the co-author of the study, Dr. Qian Yuan, quoted by the Washington Post.

Even if the hypothesis is correct, it is not clear whether modern plate tectonics can trace the origin of Theia’s impact, or whether the original explosion started, before it happened again due to reasons another.

However, if Theia’s big crash was the impetus for the trends we see today, this might be another requirement for a planet to support advanced life. The recycling of Earth’s crustal material through the mantle has been a temperature regulator for Earth before life developed the same ability, reducing extreme, hot and cold temperatures.

If only a big accident at the right time could create such a situation, Earth-like planets could be hundreds of times rarer than we think. In this case, civilization may be less possible and more valuable.

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(rns/rns)