The changing shape of Earth’s landscapes over the past 100 million years has been reconstructed in more detail than ever before.
“Earth’s surface is like the living skin of our planet – it connects all the different systems, the physical, chemical, biological, and it’s constantly evolving,” says Tristan Salles at the University of Sydney, Australia, who led the project.
Salles and his colleagues modelled the past 100 million years of surface changes on Earth by pulling together the most up-to-date existing models of tectonics, climate, the movement of sediment along rivers from mountains to oceans, and other processes that shape the landscape.
“Some models of landscape dynamics have previously been constructed to predict landslips or the stability of slopes in mines, but they have been quite local, so we had to find ways to extrapolate the modelling capability to a global scale,” says Salles.
The team validated its model by confirming it could reproduce present-day landscape dynamics, for example the sediment load that is carried along modern-day rivers.
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The results reveal, in 1-million-year increments, how the landscape has changed over time, showing features that are 10 kilometres or larger.
The model shows how the planet looked completely different 100 million years ago, with the African continent divided in half, India situated near Antarctica and North America in pieces.
“This unprecedented high-resolution model of Earth’s recent past will equip geoscientists with a more complete and dynamic understanding of the Earth’s surface,” says team member Laurent Husson at the Institute of Earth Sciences in Grenoble, France.
“Critically, it captures the dynamics of sediment transfer from the land to oceans in a way we have not previously been able to,” he says.
The model will also allow us to better understand the global carbon cycle and how changing landscapes influence biodiversity, says Salles. It will also assist with predicting the future, he says. “We expect the Earth’s surface to change just as much in the next 100 million years.”
Journal reference:
Science DOI: 10.1126/science.add2541
