When scientists consider other planetary bodies, they tend to take a holistic approach that encompasses the whole package, from the atmosphere to the core. Now, a group of researchers aim to study Earth and its history in the same way, through a new initiative entitled Earth 4D – Subsurface Science and Exploration.
The Canadian Institute for Advanced Research (CIFAR) has awarded a five-year, $3 million grant to fund Earth 4D. DCO Deep Energy Community member Barbara Sherwood Lollar (University of Toronto, Canada) and fellow program director Jack Mustard (Brown University, USA) proposed the initiative along with a dozen colleagues and collaborators, which will orchestrate new investigations into the interactions between the surface and subsurface on Earth. Ultimately, the researchers want to understand the processes affecting the three-dimensional distribution of water and life within the planet, the controlling features of the subsurface architecture, and how the subsurface environment has evolved over the fourth dimension, time. What they discover about Earth will inform the investigation of planetary processes and the search for life on Mars and other potentially habitable planets.
Several DCO-affiliated researchers will be involved with the project. “Core relationships and discussions that came out of the DCO certainly sparked some of the ideas that have been incorporated into aspects of Earth 4D, particularly around the area of Deep Life,” said Sherwood Lollar. “Earth 4D will try to transform this idea of subsurface science with a broader lens from which we look at all of the aspects of the subsurface. So it focuses not just on carbon, but on the flux and transport of water and elements necessary for life.”
The Earth 4D project is one of only four new research programs funded by CIFAR this year, from among hundreds of applications. CIFAR seeks to bring together diverse international teams to tackle big, high-risk questions in a new way. It provides “catalytic funding” that will enable small groups of researchers to meet to write critical papers, develop necessary models, and seed new spinoff projects. Since big ideas take time to develop, Sherwood Lollar and Mustard will have the opportunity to renew the grant for another five years.
One goal of the project is to develop a comprehensive model of Earth’s subsurface architecture. Borrowing the “Follow the water” mantra from Mars investigations, Sherwood Lollar wants to map out, on a planetary scale, the different regions where water travels on Earth. The top zone would be the area where surface water penetrates, followed by deeper regions with local water exchange, and the deepest zone where water is isolated. From there, they can begin to map out where life could survive.
The researchers also plan deeper investigations into places on Earth that are analogs for other planets. Earth’s marine crust is recycled on less than 200-million-year timescales via plate tectonics, but ancient continental areas, like the Canadian Shield, could stand in for Mars, to show how billion-year old rocks could support life, or preserve signs of life that was once there.
These investigations will not only yield a deeper understanding of Earth, but also will give valuable information about where – and when – life could arise on other planetary bodies. The findings will help focus future searches for life elsewhere.