Posted: 22:45, 20 June 2022 | Updated: 22:46, 20 June 2022
Scientists have created a new map of the Earth’s tectonic plates that shows the continents organized like the first supercontinent, Vaalbara, which disintegrated about 2.8 million years ago. The team, led by the University of Adelaide, believes the updated model will help better understand natural hazards such as earthquakes and volcanoes. Tectonic plates are the gradual displacement of continents on the Earth’s surface that causes earthquakes and volcanoes to erupt. Going back millions of years, scientists are able to include new microplates, such as the Macquarie microplate in southern Tasmania and the Capricorn microplate that separates the Indian and Australian plates. That allowed them to better explain “the spatial distribution of 90 percent of earthquakes and 80 percent of volcanoes over the last two million years, while existing models record only 65 percent of earthquakes,” said Dr. Derrick Hasterok. Lecturer, Department of Earth Sciences, University of Adelaide who led the team, in a statement. Scroll down for videos Scientists have created a new map of the Earth’s tectonic plates showing the continents organized like the first supercontinent, Vaalbara, which disintegrated about 2.8 million years ago. To achieve these statistics, Hasterok and his team also added more accurate information about deformation zone boundaries: previous models showed them as discrete areas rather than wide bands. “The biggest changes to the plate model have taken place in western North America, which often borders the Pacific plate as far as the San Andreas and Queen Charlotte faults,” Hasterok said. “But the recently demarcated border is much wider, about 1,500 km [932 miles]from the previously designed narrow band. “The other big change is in Central Asia. The new model now includes all the deformation zones in northern India, as the slab is bulldozed to Eurasia. This allowed them to better explain “the spatial distribution of 90 percent of earthquakes and 80 percent of volcanoes over the last two million years, while existing models (photo) record only 65 percent of earthquakes.” The last time the tectonic plate model was updated was in 2003. “The slab model can be used to improve geothermal hazard models. “The orogeny model helps to understand the geodynamic systems and the best model of Earth evolution and the provincial model can be used to improve the search for minerals,” said Hasterok. A separate study, published in 2019, supports the new model, as it found that tectonic plates began to form about 2.5 billion years ago – shortly before Vaalbara disintegrated. To estimate when the Earth’s tectonic plates began, geologist Robert Holder of Johns Hopkins University in Baltimore and his colleagues studied metamorphic rocks from 564 sites around the world dating back 3 billion years. Metamorphic rocks are those formed when other types of rocks – those produced by sediments or cooled by lava or magma – change either through extreme temperatures or under pressure. Going back millions of years, scientists are able to include new microplates, such as the Macquarie microplate in southern Tasmania and the Capricorn microplate that separates the Indian and Australian plates. By analyzing these rocks, the team could determine the depths and temperatures at which they formed, creating an image of the changing heat flow at various points throughout the Earth’s crust – and, in turn, the plate tectonics it controls. that’s all. The author of the work and geologist at Curtin University, Tim Johnson, said in a statement: “Some geologists believe that the Earth has had plate tectonics throughout its four and a half billion years of existence. “While others believe that plate tectonics appeared abruptly about a billion years ago. “Using a simple statistical analysis of the temperature, pressure and age of the metamorphic rocks, we discovered that plate tectonics evolved gradually over the last 2.5 billion years as our planet slowly cooled.”
The Earth moves beneath our feet: Tectonic plates move through the mantle and produce earthquakes as they scratch each other
The tectonic plates consist of the Earth’s crust and the upper part of the mantle. Below is the sphere: the hot, viscous rock conveyor belt on which the tectonic plates move. The Earth has fifteen tectonic plates (in the photo) that together have formed the shape of the landscape we see around us today. Earthquakes usually occur at the boundaries of tectonic plates, where one plate sinks beneath the other, pushes another up, or where the edges of the plates are scraped side by side. Earthquakes rarely occur in the middle of the slabs, but can occur when ancient cracks or fissures well below the surface are reactivated. These areas are relatively weak compared to the surrounding slab and can easily slip and cause an earthquake.
