The tectonic plates that cover Earth like a jigsaw puzzle move about as fast as our fingernails grow, but over the course of a billion years that’s enough to travel across the entire planet – as a fascinating new video shows.
In one of the most complete models of tectonic plate movements ever put together, scientists have condensed a billion years of movement into a 40-second video clip, so we can see how these giant slabs of rock have interacted over time.
As they move, the plates affect climate, tidal patterns, animal movements and their evolution, volcanic activity, the production of metals and more: they’re more than just a covering for the planet, they’re a life support system that affects everything that lives on the surface.
“For the first time a complete model of tectonics has been built, including all the boundaries,” geoscientist Michael Tetley, who completed his PhD at the University of Sydney, told Euronews.
“On a human timescale, things move in centimetres per year, but as we can see from the animation, the continents have been everywhere in time. A place like Antarctica that we see as a cold, icy inhospitable place today, actually was once quite a nice holiday destination at the equator.”
The moving and sliding of the plates is quite a sight if you check out the video – land masses that are near neighbours become distant cousins and vice versa, and you might be surprised at just how recently it was that the countries and continents settled into the positions that we know today.
Understanding these movements and patterns is crucial if scientists want to predict how habitable our planet will be in the future, and where we’re going to find the metal resources we need to ensure a clean energy future.
Plate movement is estimated through the study of the geological record – the magnetism that provides data on substrates’ historic positions in respect to Earth’s spin axis and the types of material locked in rock samples that help match the pieces of past geological plate puzzles together.
Here the team went to great lengths to choose and combine the most suitable models currently available, looking at both the movements of the continents and the interactions along plate boundaries.
“Planet Earth is incredibly dynamic, with the surface composed of plates that constantly jostle each other in a way unique among the known rocky planets,” says geoscientist Sabin Zahirovic, from the University of Sydney.
“These plates move at the speed fingernails grow, but when a billion years is condensed into 40 seconds a mesmerising dance is revealed. Oceans open and close, continents disperse and periodically recombine to form immense supercontinents.”
The further scientists go into the past, the more difficult it becomes to estimate how plates have moved, and in this case the Neoproterozoic to Cambrian (1,000 to 520 million years ago) eras in particular were carefully charted and brought in line to match the more modern records that we have.
Questions remain about how these plates first formed and when this formation happened, but every new data point helps us to understand the ancient history of Earth – even accounting for missing plates in some models.
The scientists admit that their work lacks some finer detail – stretched as it is across the entire planet and a billion years – but they’re hoping that it can act as a useful resource and foundation for the future study of these movements and the impact they have on everything else on the planet.
“Our team has created an entirely new model of Earth evolution over the last billion years,” says geoscientist Dietmar Müller, from the University of Sydney.
“Our planet is unique in the way that it hosts life. But this is only possible because geological processes, like plate tectonics, provide a planetary life-support system.”
The research has been published in Earth-Science Reviews.