How has the transfer and accumulation of sediment from land to oceans affected Earth’s geomorphology?

Scientists have published new research revealing a detailed and dynamic model of the Earth’s surface over the past 100 million years. The model simulates landscape evolution caused by erosion and deposition over the past 100 million years.

Developed by geoscientists at the University of Sydney in collaboration with scientists in France, the model provides a good understanding of how today’s geophysical landscapes formed and how millions of tons of sediment have flowed to the oceans.

Lead author Dr. Tristan Salles from the University of Sydney, School of Geosciences, said: “To predict the future, we need to understand the past. But our geological models have provided only a fragmented understanding of how our planet’s recent physical features have formed.

“If you’re looking for a continuous model of the interaction between river basins, global-scale erosion and high-resolution sediment deposition over the past 100 million years, it just doesn’t exist.”

“So this is a big step forward. Not only is it a tool to help us investigate the past, but it will also help scientists understand and predict the future.”

Using a framework integrating geodynamics, tectonic and climatic forces with surface processes, the scientific team has presented a new dynamic model of the past 100 million years at high resolution (up to 10 kilometers), divided into frames of one million year.

Second author Dr. Laurent Husson of Institut des Sciences de la Terre in Grenoble, France, said: “This unprecedented high-resolution model of the Earth’s recent past will equip geoscientists with a more complete and dynamic understanding of the Earth’s surface.

“Critically, it captures the dynamics of sediment transfer from the land to the oceans in a way we couldn’t before.”

Dr. Salles said so “Understanding the flow of terrestrial sediment to marine environments is vital to understanding current ocean chemistry.”

“As ocean chemistry is changing rapidly due to human-induced climate change, a complete picture can help us understand marine environments.”

The model allows scientists to explore different hypotheses about how the Earth’s surface will respond to shifting tectonic and climate factors.

The study also provides a better model for understanding how sediment movement controls the carbon cycle over millions of years.

Dr Salles said: “Our findings will provide scientists in other fields with a dynamic and detailed background to prepare and test hypotheses, such as in biochemical cycling or biological evolution.”

Magazine reference:

  1. Tristan Salles, Laurent Husson et al. One hundred million years of landscape dynamics from watershed to global scale. Science. DOI: 10.1126/science.add2541