Updated maps of plate tectonics

New models that show how the continents are grouped offer new insights into Earth’s history and will help provide a better understanding of natural hazards such as earthquakes and volcanoes.

“We looked at current knowledge of the formation of plate boundary zones and the previous structure of the continental crust,” said Dr Derek Hasrock, lecturer in the Department of Earth Sciences at the University of Adelaide who led the team that produced the new models.

“The continents are put together from a few pieces at a time, a bit like a jigsaw, but each time a puzzle is completed, it is sliced ​​up and reorganized to produce a new picture. Our study helps shed light on the different components so that geologists can piece together the images. previous together.

“We found that plate boundary regions account for approximately 16 percent of the Earth’s crust and an even higher proportion, 27 percent, of the continents.”

“Our new model of plate tectonics better explains the spatial distribution of 90 percent of earthquakes and 80 percent of volcanoes from the past two million years while current models capture only 65 percent of earthquakes.”

– Dr.. Derek Hasrock, Lecturer, Department of Earth Sciences, University of Adelaide

New models show the architecture of the Earth. Credit: Dr Derek Hasrock, University of Adelaide

The team produced three new geological models: a plate model, a county model, and an origin formation model.

“There are 26 mountain types – the process of mountain formation – that have left an imprint on the current architecture of the crust. Many, but not all of these, are related to the formation of supercontinents,” said Dr. Hasrock.

“Our work allows us to update the maps of plate tectonics and the formation of continents found in textbooks. These plate models compiled from global topographic and earthquake models have not been updated since 2003.”

The new plate model includes several new microplates including the Macquarie plate located in southern Tasmania and the Capricorn plate that separates the Indian and Australian plates.

“To further enrich the model, we added more precise information about the boundaries of the deformation regions: previous models showed these as discrete regions rather than broad regions,” Dr. Hasrock said.

“The largest changes to the plate model have been in western North America, which often has boundaries with the Pacific Plate painted with the names of San Andreas and Queen Charlotte Vaults. But the newly demarcated boundary is much wider, about 1,500 km, than the narrow zone drawn previously.

The other big change is in Central Asia. The new model now includes all regions of deformation north of India as the plate makes its way into Eurasia.”

A tale told by the continents. Credit: Dr Derek Hasrock, University of Adelaide

Published in the magazine geology ReviewsThe team’s work provides a more accurate representation of Earth’s architecture and has other important applications.

“Our new model of plate tectonics better explains the spatial distribution of 90 percent of earthquakes and 80 percent of volcanoes from the past two million years while current models capture only 65 percent of earthquakes,” Dr. Hasrock said.

“The plate model can be used to improve risk models of geographical hazards; the mountain formation model helps to understand geodynamic systems and provide a better model of the Earth’s evolution and the county model can be used to improve mineral exploration.”

Reference: “New Maps of Global Geoparks and Tectonic Plates” by Derek Hasrock, Jacqueline A. Halpin, Alan S. Collins, Martin Hand, Korn Kramer, Matthew Gard, and Stijn Glory, May 31, 2022, geology Reviews.
DOI: 10.1016 / j.earscirev.2022.104069

The work involved researchers at the universities of Adelaide, Tasmania, Nevada Reno and Geoscience Australia.