Dietmar Muller, geophysicist

Dietmar Muller’s primary research focus is the physical fabric of the world and how it has evolved over more than a billion years, reaching back to a time when life as we know it didn’t exist. Using the latest advances in machine learning and computing technology, the Sydney University geophysicist and his colleagues use the geophysical and geochemical signatures of preserved rock to reconstruct the way continents have formed, collided and disintegrated and the implications for today’s world.

Muller and collaborating scientists around the world have built powerful interactive online tools to better visualise the Earth’s plate tectonic evolution. Using their four-dimensional computer models, the movements of continents and the evolution of ocean basins can be seen in a time-lapse movie, with millennia passing in seconds.

“I’ve spent much of my career looking at the evolution of the Earth in the last 200-250 million years, from the time when the Pangea super-continent existed to today,” he says.

“But we are now pushing the tectonic reconstructions and the dynamic models of the Earth’s interior much further back in time. There was a previous super-continent, Rodinia, that existed about 1.1 billion years ago.” He and his colleagues are now working on models that reach back that far.

In one of his most cited research projects, Muller and his team used big data analysis to build the first digital map of the age of the world’s ocean floor. They have also predicted – correctly – where opal deposits might be found in northern NSW and uncovered a link between certain very large earthquakes and the structure of the Pacific Ocean’s crust. They are now working with a large mining company to develop and apply new “deep time” data analysis techniques that could help find copper deposits.

Muller first studied science at Christian-Albrechts University in northern Germany, and with an undergraduate degree under his belt, he moved to the US, winding up at the renowned Scripps Institute of Oceanography at the University of California in San Diego.

In 1993, with a doctorate from one of the world’s foremost oceanographic institutes, Muller began looking for a job. Sydney University responded to one of his applications and, after a phone interview, offered him work as a lecturer. He had never been to Australia, but he bought a one-way ticket, and he has worked the same university ever since, marrying a fellow Australian geologist.

He was in the US, though, at just the right time. In the mid-80s, the first computers were becoming useful scientific tools, and providentially for Muller, many of the huge computing advances were happening in Texas and California – to the delight of US-based scientists.

“There was a generation of 3D graphics computers that came out which didn’t exist in Germany at all,” Muller remembers, adding that with negligible power (about the same as a tablet today) one of these early computers had a graphics interface linked to a computer the size of a fridge.

“It was really attractive, because at that time the first software was being developed to manipulate images of tectonic plates on a spherical surface, the globe,” he says.  Muller was on hand when this revolutionary technology was first offered to geophysicists and he has used it to the full ever since.

“I was one of the few people who had this technology at my fingertips,” he says. “This is how I became truly fascinated by plate tectonics and deep geological time.”