Most detailed geological model reveals Earth's last 100 million years

For the first time, a high-resolution dynamic model of the Earth's surface over the past 100 million years has been developed, according to a study published in Science on March 2. 

The detailed model will enable researchers to test different hypotheses on how the Earth's surface may react to shifting tectonic and climate factors. It will also boost knowledge of how the movement of Earth's sediment controls the carbon cycle over time. 

How has Earth's surface changed over time?

The interaction of climate, tectonics, and time produces powerful forces that shape the surface of our planet. What appears to be as solid as a rock is continually changing- for instance, even mountains constantly evolve.

"To predict the future, we must understand the past. But our geological models have only provided a fragmented understanding of how our planet's recent physical features formed," said lead author Dr. Tristan Salles from the University of Sydney School of Geosciences in a press release. 

He states that a continuous model of the interactions between river basins, global-scale erosion, and sediment deposition during the past 100 million years simply doesn't exist.

Of course, until now. 

By mixing geodynamics, tectonic, and climatic forces with surface activities, the scientific team developed a model over 100 million years (down to kilometer-scale) that can be divided into frames of a million years.

"So, this is a big advance. It's not only a tool to help us investigate the past but will help scientists understand and predict the future, as well," claimed Salles. Additionally, he explained that understanding the flow of terrestrial sediment to marine environments is vital to comprehend present-day ocean chemistry:

"Given that ocean chemistry is changing rapidly due to human-induced climate change, having a more complete picture can assist our understanding of marine environments."

Second author Dr. Laurent Husson from Institut des Sciences de la Terre in Grenoble, France, stated, "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."

"Critically, it captures the dynamics of sediment transfer from the land to oceans in a way we have not previously been able to."

The team's high-resolution Earth model will ultimately provide researchers in various fields with a dynamic and comprehensive foundation to better develop and test theories in areas beyond the carbon cycle, such as biochemical cycles or biological evolution.

The complete study was published in Science on March 2 and can be found here.

Study abstract:

Our capability to reconstruct past landscapes and the processes that shape them underpins our understanding of paleo-Earth. We take advantage of a global-scale landscape evolution model assimilating paleoelevation and paleoclimate reconstructions over the past 100 million years. This model provides continuous quantifications of metrics critical to the understanding of the Earth system, from global physiography to sediment flux and stratigraphic architectures. We reappraise the role played by surface processes in controlling sediment delivery to the oceans and find stable sedimentation rates throughout the Cenozoic with distinct phases of sediment transfer from terrestrial to marine basins. Our simulation provides a tool for identifying inconsistencies in previous interpretations of the geological record as preserved in sedimentary strata, and in available paleoelevation and paleoclimatic reconstructions.