A new “unprecedented” animation of Earth shows how the planet’s surface has shifted and changed over the past 100 million years.
This animation is the most detailed display of the history of Earth’s topography ever, depicting the rise of mountains, the development of basins, and the transport of large masses of sediment around the world through erosion.
Animation shows movements tectonic platesLarge groups of crust colliding with each other to form mountain ranges and breaking apart to form ocean basins. When these plates sink into the mantle, or the middle layer of the Earth, in subduction zones, they give rise to volcanoes and earthquakes that shape the planet. But other forces shape the surface as well: precipitation erodes the surface, while the rate of weathering changes carbon dioxide levels in the air, creating a feedback loop connecting the land with the atmosphere.
“While the dance of the continents has been widely studied,” he said, “we are still limited in our understanding and representation of how the Earth’s surface evolved.” Tristan Sales (Opens in a new tab)a senior lecturer in geosciences at the University of Sydney and lead author of a new paper describing the model, which was published March 2 in the journal Sciences (Opens in a new tab).
“What we’re bringing with this new model is a way to assess how this surface has changed (globally and on geological time scales) through its interactions with the atmosphere, hydrosphere, tectonics, and mantle dynamics,” Sales wrote in an email to Live Science.
Related: Small magma mass may rewrite Earth’s history in plate tectonics
The model begins 100 million years ago in the midst of disintegration The supercontinent Pangeathat began about 200 million years ago. At the beginning of the animation, the continents that will become Africa and South America are already recognizable, as the continents of the Northern Hemisphere meet together after tens of millions of years. Blue shows the flow of water, while red shows the intensity of new sediment deposition by erosion.
“This unprecedented high-resolution model of Earth’s recent past will provide Earth scientists with a more complete and dynamic understanding of the Earth’s surface,” said a co-author of the study. Laurent Hussein (Opens in a new tab)a geoscientist at the Institute of Geosciences (ISTerre) in Grenoble, France, said in A statement (Opens in a new tab).
Combining all of these different pressures on Earth’s evolution, from plate motions to water flow to slow changes in the mantle, provides a new way to ask questions about everything from climate regulation to the ways atmospheric circulation affects Earth’s erosion.
The researchers found that the rate of movement of sediments around the world was likely much greater than scientists thought based on observation, possibly because the sedimentary record is fragmentary. Overall rates of erosion have remained fairly constant over the past 100 million years, Sales said, but there have been changes in whether sediments end up trapped in low-altitude basins on land or eventually flow into the sea. For example, there was a doubling of sediment flow into the oceans about 60 million to 30 million years ago, which is likely related to the uplift of the Himalayas and the Tibetan plateau, the researchers wrote.
Such nuances can be important, Sales said. For example, some of the earliest forms of life formed in shallow marine environments, where microorganisms first harnessed photosynthesis and left behind mineral formations known as stratolites.
“It is thought that sedimentation flux may be a source of nutrients for these early organisms, allowing them to grow and evolve over time,” Sales said. “We envision that our model can be used to test such long-standing hypotheses regarding the origin of life on Earth.”
“Devoted student. Bacon advocate. Beer scholar. Troublemaker. Falls down a lot. Typical coffee enthusiast.”