Understanding the evolution of our planet requires a research team that spans the globe, but Professor Zheng-Xiang Li, from Curtin’s department of Applied Geology, is at its epicentre.
Like the centre of an earthquake, Professor Li’s research ripples have been felt widely, with his recognition as a Thomson Reuters Highly Cited Researcher in 2014. The ripples will now propagate further, with Professor Li awarded a five-year, $2.9 million Australian Laureate Fellowship from the Federal Government in June – one of only 15 awarded nationally. This will support his Fellowship project, ‘How the Earth Works’ towards building a new tectonic paradigm.
“Plate tectonic theory was developed in the 1960s, and gave us a dynamic view of the Earth’s surface – with plates colliding to form mountain ranges, and drifting apart to widen oceans. It explains what we see on the surface,” says Professor Li, “but it doesn’t explain why. What forces drive the plate movements? How does the Earth ‘engine’ really work? Answering these questions is fundamental to understanding this planet, reconstructing its history, and predicting its future.”
Progressing our understanding of the dynamic Earth has only become possible over the last 10–20 years, with the development of several new technologies. Seismic tomography now allows us to see the deeper internal structure of the Earth’s mantle, and can track the movements of ocean plates pushed down under the crust, as well as the upward motion of hot rocks in the mantle.
Rapidly expanding databases of palaeomagnetic and geological information have extended our understanding of supercontinent history from just the last 540 million years to 1,000 million years ago and beyond: before Gondwanaland and Pangea to the previous supercontinent Rodinia, with glimpses even further back.
Advances in supercomputing tie it all together: reconstructing the seismic data, collating the databases, and allowing the development of sophisticated models to simulate geodynamic processes. Researchers can now simulate plate tectonic and deep mantle processes occurring over hundreds of millions of years.
“We are starting to realise that the Earth’s history has been dominated by supercontinent cycles, where the land masses come together, then break up again,” explains Professor Li.
“Our current hypothesis links supercontinent evolution with superplume events in the mantle, and this fellowship project will collect and combine paleomagnetic and geological data worldwide to test and refine our model. We aim to revolutionise understanding of the inner workings of the dynamic Earth, and thereby extend our knowledge of the Earth’s history back 2,000 million years.”
Along the way, the international collaborative effort will establish global geological, geotectonic, paleomagnetic, and mineral deposit databases, and new tools to collate and organise the data. These will be made freely available to researchers and industry, with widespread application to resource exploration, fossil and evolution studies, and climate modelling.