The Earth is estimated to be about 4.5 billion years old, and life first appeared about 3 billion years ago.
To unravel this incredible history, scientists used a range of different techniques to identify the many components involved.
They determined when and where continents moved, how life evolved, how did climate change over time? When do our oceans rise and fall, how land is formed… Tectonic plates – large, constantly moving pieces of rock that make up the Earth’s outermost layer (crust) are at the heart of all these studies.
Together with their colleagues, the scientists published a global tectonic map of the Earth over half a billion years of Earth’s history, from 1,000 million years ago to 520 million years ago.
This period is extremely important. This was the period when the Earth experienced the most extreme climate changes known, from ice ages to superheated greenhouses, from an oxygen-filled atmosphere to the emergence of multicellular life and biodiversity explosion.
Now, with the first appearance of a global map of phased plate tectonics, we can begin to assess the role of plate tectonic processes on Earth systems. land. We can even address the motions of deep-Earth structures that change over a billion-year cycle.
The tectonic plate boundaries of the modern Earth are mapped in great detail.
With Earth in modern times, global positioning satellites are used to map Earth’s changes and movements.
Geological mapping of the Earth. (Photo: Alan Collins).
We know that rocks that have heated up from a depth of 2,500km in the planet’s mantle (the layer below the Earth’s crust), have reached the planet’s solid mantle (the crust and upper part of the mantle). ). This forces the rigid surface tectonic layers to move at the growth rate of these movements.
On the other side of the rising dunes and hot rock are areas known as subduction zones – these are where large swaths of the ocean floor are pushed into the depths. Finally, oceanic tectonic plates fall to the boundary between the Earth’s core and mantle at a depth of about 2,900km. They combine with each other and form a heat or chemical accumulation.
For geologists, this map is an extremely useful tool. But when trying to look back at how the Earth has changed over time, scientists also encounter many problems. Our planet can only be mapped from here to 200 million years ago.
Before that, over a period of four billion years, most of the planet’s surface had been lost. Because all the crust under the ocean has been destroyed. The oceanic crust does not last long, but is constantly being pulled back into the depths of the Earth – making it inaccessible to scientists.
So what have scientists done to be able to map the Earth from the days it was formed? To get the location of the boundaries and their changes, scientists have been looking for representations that can replace the boundaries in the geological record.
The researchers found rocks that formed on shrinking zones, during continental collisions, or in fissures from which geological plates split. Their data comes from rocks found in locations including Madagascar, Ethiopia and far-western Brazil.
Earth Map and related work is the result of many decades of work by outstanding students, PhDs and colleagues from all over the world.
We now have more detail and material to study Earth and more ways to continue to trace our planet’s geological time. Using a variety of combined methods, the latitudes of past continents can be found – as some ferromagnetic rocks froze during their formation.
This is like a fossil compass, with the needle pointing to the ground at an angle relative to the latitude it formed. Near the equator, the magnetic field is roughly parallel to the Earth’s surface at the poles, it drops directly.