Lab+Life Scientist Oct/Nov 2016

Page 48

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.

© Shebeko

and pizza dough


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


been plenty of instances where plates have suddenly sped up during supercontinent breakup.”

48 | LAB+LIFE SCIENTIST - Oct/Nov 2016

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. |