tectonics Adam Florance
Plate tectonics
The Earth’s crust has more in common with pizza dough than you might think, according to an international team looking into the mechanics of plate tectonics.
© stock.adobe.com/au/Maksim Shebeko
and pizza dough
C
ontinental drift and the incremental
Earth’s mantle had taken place during continental
movement of the Earth’s surface has been fairly
separation. The subsequent big data analysis
well understood for some time now, but one
required high-performance computing in an open-
phenomenon that has been difficult to explain is
innovation framework.
the occasional lurch as continents uncouple.
the actions of your local pizzaiola: “Imagine
relentless grinding and pulling, but when the
you’re pulling apart a thick piece of dough. At
supercontinent does eventually split, there is a full-
first, separating it requires a lot of effort because
margin rupture and rapid acceleration as the outer
the dough resists your pulling and stretches slowly
rims of the continents plunge into the gaping abyss.
between your hands. If you’re persistent, you’ll
Professor Dietmar Müller of the University
eventually reach a point where the dough becomes
of Sydney’s School of Geosciences explained:
thin enough to separate quite easily and quickly. The
“Plates tend to shift around quite slowly because
same principle applies to rifting continents once
they’re sitting on an otherwise very viscous mantle.
the connection between them has been thinned
However, throughout Earth’s history, there have
sufficiently.”
been plenty of instances where plates have suddenly sped up during supercontinent breakup.”
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Professor Müller compares the results with
It starts with millions of years of slow but
According to lead author Dr Sascha Brune of the University of Potsdam: “This breakup
Professor Müller’s team has joined forces with
process leads to margin segmentation, where rapid
the German Research Centre for Geosciences at the
subsidence, high heat flow and enhanced volcanism
University of Potsdam to analyse the seismic data
characterise the outer margin.”
and develop sophisticated computer simulations
This research is part of the Basin Genesis Hub,
to help explain this two-phase separation process.
a five-year project at the University of Sydney
Thousands of kilometres of seismic profiles
co-funded by industry and the Australian Research
had to be laboriously analysed to determine the
Council. Interactive models of the group’s work can
exact areas where this vigorous stretching of the
be viewed at the Virtual Earth Laboratory.
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