Startling Discovery: Early Earth’s Magma Ocean Solidified in Record Time

Recent research has made a startling revelation about the ancient history of our planet. Scientists have long believed that it took hundreds of millions of years for the old Earth’s oceans of magma to solidify. However, a groundbreaking new study has shown that this process happened much faster than previously thought, in just a few million years. These discoveries shed new light on the evolution of our planet and challenge existing theories about its formation.

The current scientific consensus is that the Earth was formed around 4.54 billion years ago. This age is based on radiometric dating of rocks and meteorites and other types of evidence. The formation of the Earth began with the accretion of dust and gas in the early solar system, gradually forming larger bodies through collisions and gravitational attraction. Eventually, these bodies grew large enough to become planetesimals, which then combined to form protoplanets. The protoplanet that would become Earth grew by collisions and gravitational pull until it reached its current size.

The process of the formation of the Earth was complex and took place over a long period of time, but it ultimately led to the formation of a planet particularly suitable for life. But long before becoming a haven for life, the Earth underwent hellish transformations. Now scientists at Florida State University are shedding light on the ocean of magma that covered ancient Earth and how long it took for it to solidify.

An ocean of magma

The study published in Nature Communications reveals that the ocean of magma that covered the Earth at the start of its formation took less than two million years to solidify. This ocean of magma stretched for thousands of miles into the Earth’s core. The cooling rate of this magmatic ocean has influenced the formation of the different layers of the planet and its chemical composition.

Previous research estimated that it took hundreds of millions of years for this magmatic ocean to solidify, but the new Florida State University (FSU) study has drastically reduced those uncertainties “to less than a few million years”. . According to Mainak Mookherjee, associate professor of geology in the Department of Earth, Ocean and Atmospheric Sciences, the magmatic ocean has played an important role in Earth’s history, and this research helps answer questions fundamentals on the planet.

How do they know?

But how do scientists know? It turns out that when magma cools, it forms crystals. What happens to these crystals depends on the viscosity of the magma and the density of the crystals. Denser crystals sink. This in turn changes the composition of the magma. As scientists explain, the rate at which magma solidifies depends on its viscosity. A less viscous magma allows faster cooling. Thicker magma allows longer cooling. Professor Mookherjee and his colleagues ran simulations that lasted six months using the FSU High Performance Computing Center and the National Science Foundation Computing Center.

Suraj Bajgain, a former post-doctoral researcher at FSU and currently a visiting assistant professor at Lake Superior State University, noted that Earth’s sheer size means the pressure at depth is likely extremely high. He explained that even though the viscosity of magma at the surface is known, determining the viscosity hundreds of kilometers below the surface is a formidable task.

In addition, the study sheds light on the origin of the chemical variations observed in the lower mantle of the Earth. Earth scientists have long been baffled that lava samples from deep ocean ridges and volcanic islands like Hawaii and Iceland are solidifying into basalt rocks that look similar but have different chemical properties. dissimilar.

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