Researcher Develops Electrons To Predict Earth’s Surface Evolution

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Our planet’s surface evolves continuously by a complex interplay of climate, biological processes, and tectonic activity. Rapid population growth and climate change are modifying our landscapes, including soils, mountains, coasts, and rivers in an unprecedented manner.

However, we are unable to reliably predict these changes because of our poor understanding of how our landscapes have evolved over the last tens to tens-of-thousands of years. The main hurdle is a conspicuous lack of techniques that can estimate the rates of Earth surface processes such as mountain uplift and sediment erosion and transport by river, glacier, wind, and biological activity over such recent time scales.

“Ultimately landscape is the engine of life. What sustains life on Earth is the delivery of nutrients from point A to point B in the form of sediments transported, for example from the mountains to the sea, or from a rock to a soil that develops over it. And we need to be able to quantify the rates at which such sediment production and distribution occurs,” explains Mayank Jain, who is group leader at DTU Physics.

Determining the rate at which these Earth surface processes operate under different geological and climatic conditions is fundamental to understanding and predicting landscape evolution.

“While we can perform experiments to measure the current rates of Earth surface processes with great accuracy, these rates are not representative of how Earth’s surface is evolving over the long term. To fully describe the landscape evolution, we need robust time-series data, especially over the recent time scales. My aim is to fill this gap in knowledge by establishing much needed tools that will enable us to obtain such data,” Mayank Jain says.

The Senior Researcher has been awarded a EUR 3 mio. Advanced Grant from the European Research Council, ERC for his inter-disciplinary project LUMIN (Illuminating charge transport in feldspar to measure rates of Earth surface processes). It is earmarked research that will come up with a physical and mathematical model that will allow us to accurately determine the rate at which Earth’s surface has evolved over recent times.

“Without a robust quantitative method, we risk major bias in our perception of how Earth’s surface has evolved in the recent past. This bias can be detrimental to predicting our planet’s response to rapid climate change, and hence our initiatives to restore our environment,” Mayank Jain says.

The ultimate model
The five-year research project has two main parts.

The first part is to gain a deeper physical understanding of how feldspar—the most common mineral on Earth’s crust—captures and releases electrons as it is exposed to radioactivity, heat, and sunlight during its passage from point A to B on the surface of Earth.

“Despite seven decades of research, the details of this process are not known because of a lack of tools to directly examine the trapped electrons in the crystal,” Mayank Jain explains. This work will build on a breakthrough discovery by his group at DTU Physics that lets researchers map the distribution of trapped electrons in feldspar. It will entail developing new instruments.

The second part is to develop a comprehensive theory of electron capture and release in feldspar. Understanding more fully the electron transport in feldspar will enable Mayank Jain and his team to establish the ultimate model that can accurately describe the rates at which e.g., rock is turned into soil, mountains are uplifted, or sediment is transported from the source of a river to where it meets the sea.

“Such a model will fundamentally redefine how we understand our planet’s surface, by enabling us to study its evolution over the last tens to tens of thousands of years,” Mayank Jain says.

Being able to accurately predict such changes to Earth’s landscapes will help guide decisions on how we use the land and manage geohazards—including those brought about by climate change.
The model framework will also allow investigation of transport pathways of electrons in other light emitting materials to support development of ideal photonic materials for applications in health and environment. The work has potential to even help us to understand how the landscape on Mars has evolved by studying the samples that will be brought back from there.