New tectonic plate model shows how Earth was organized as a supercontinent 2.8 million years ago

New tectonic plate model shows how Earth was organized as a supercontinent 2.8 million years ago

A new tectonic plate model shows how Earth was organized as a supercontinent 2.8 million years ago: scientists hope it will help predict natural hazards like earthquakes and volcanoes

  • A new model of Earth’s tectonic plates aims to help us better understand earthquakes and volcanoes
  • The model organizes the continents as the first supercontinent, Vaalbara
  • Vaalbara split about 2.8 million years ago
  • Using this design allowed scientists to include more microplates
  • This allowed them to better explain “the spatial distribution of 90% of earthquakes and 80% of volcanoes of the last 2 million years”.

Scientists have produced a new map of Earth’s tectonic plates that shows continents organized like the first supercontinent, Vaalbara, which collapsed around 2.8 million years ago.

The team, led by the University of Adelaide, believe the updated model will help better understand natural hazards such as earthquakes and volcanoes.

Tectonic plates are the gradual drift of continents on the Earth’s surface that causes earthquakes and volcanic eruptions.

Going back millions of years ago, scientists are able to include new microplates, such as the Macquarie microplate which lies south of Tasmania and the Capricorn microplate which separates the Indian and Australian plates.

This allowed them to better explain “the spatial distribution of 90% of earthquakes and 80% of volcanoes over the past two million years, whereas existing models only capture 65% of earthquakes,” said Dr. Derrick Hasterok, Lecturer, Department of Earth Sciences, University. of Adelaide who led the team, in a statement.

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Scientists have produced a new map of Earth's tectonic plates that shows continents organized like the first supercontinent, Vaalbara, which collapsed around 2.8 million years ago

Scientists have produced a new map of Earth’s tectonic plates that shows continents organized like the first supercontinent, Vaalbara, which collapsed around 2.8 million years ago

To obtain these statistics, Hasterok and his team also added more precise information about the boundaries of the deformation zones: previous models showed them as discrete areas rather than large areas.

“The biggest changes to the plate model have taken place in western North America, which often has the boundary with the Pacific plate drawn like the San Andreas and Queen Charlotte faults,” said Hasterok.

“But the newly demarcated border is much wider, about 1500 km [932 miles]than the narrow area drawn earlier.

“The other big change is in Central Asia. The new model now includes all deformation zones north of India as the plate pushes its way towards Eurasia.

This allowed them to better explain

This allowed them to better explain “the spatial distribution of 90% of earthquakes and 80% of volcanoes over the past two million years, whereas existing models (pictured) only capture 65% of earthquakes” .

The last update of the tectonic plate model dates back to 2003.

“The plate model can be used to improve geohazard hazard models; the orogeny model helps to understand geodynamic systems and better model the Earth’s evolution and the province model can be used to improve mineral prospecting,” Hasterok said.

A separate study, published in 2019, supports the new model, as it found that tectonic plates began to form around 2.5 billion years ago – shortly before Vaalbara erupted.

To assess the beginning of Earth’s tectonic plates, geologist Robert Holder of Johns Hopkins University in Baltimore and his colleagues studied metamorphic rocks from 564 sites around the world that date back 3 billion years.

Metamorphic rocks are those that form when other types of rock—those made from sediment or cooled by lava or magma—are weathered by extreme temperatures or pressures.

Going back millions of years ago, scientists are able to include new microplates, such as the Macquarie microplate which lies south of Tasmania and the Capricorn microplate which separates the Indian and Australian plates.

Going back millions of years ago, scientists are able to include new microplates, such as the Macquarie microplate which lies south of Tasmania and the Capricorn microplate which separates the Indian and Australian plates.

By analyzing these rocks, the team was able to determine the depths and temperatures at which they formed, creating a picture of how the heat flow changes at different places in the earth’s crust – and, in turn, the plate tectonics that control it.

The author of the paper and Curtin University geologist Tim Johnson said in a statement: “Some geologists consider the Earth to have had plate tectonics throughout its four and a half billion years of existence. “

“While others consider that plate tectonics appeared suddenly about a billion years ago.

“Using a simple statistical analysis of the temperature, pressure and age of metamorphic rocks, we revealed that plate tectonics have evolved gradually over the past 2.5 billion years while that our planet was slowly cooling.”

The Earth moves under our feet: tectonic plates move through the mantle and produce earthquakes by rubbing against each other

Tectonic plates are made up of the earth’s crust and the upper part of the mantle.

Below is the asthenosphere: the hot, viscous conveyor belt of rock on which the tectonic plates roll.

The Earth has fifteen tectonic plates (pictured) which together shaped the shape of the landscape we see around us today

The Earth has fifteen tectonic plates (pictured) which together shaped the shape of the landscape we see around us today

Earthquakes typically occur at tectonic plate boundaries, where one plate dips under another, pushes another up, or where the edges of plates rub against each other.

Earthquakes rarely occur in the middle of plates, but they can occur when old faults or fissures well below the surface reactivate.

These areas are relatively weak compared to the surrounding plate and can easily slip and cause an earthquake.

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