A new understanding of the Earth’s architecture: updated maps of tectonic plates

New model of tectonic plate with boundary zones in darker shadows. Credit: Dr. Derrick Hasterok, University of Adelaide

New models that show how the continents were formed provide fresh insights into the Earth’s history and will help to better understand natural hazards such as earthquakes and volcanoes.

“We looked at current knowledge of plate boundary zone configuration and past continental crust construction,” said Dr. Derrick Hasterok, a lecturer in the Department of Earth Sciences at the University of Adelaide who led the team that produced the new models.

“The continents were put together in several parts, a bit like a jigsaw puzzle, but every time the jigsaw puzzle was done, it was cut and reorganized to produce a new picture. Our study helps to illuminate various components so that geologists can compile previous images.

“We found that the boundary zones of the plates make up almost 16 percent of the Earth’s crust and an even larger share, 27 percent, of the continents.

“Our new model for tectonic plates better explains the spatial distribution of 90 percent of earthquakes and 80 percent of volcanoes from the last two million years, while existing models cover only 65 percent of earthquakes.”

Dr. Derrick Hasterok, Lecturer, Department of Earth Sciences, University of Adelaide

https://www.youtube.com/watch?v=BIDKs6_I-S5g
New models showing the architecture of the Earth. Credit: Dr. Derrick Hasterok, University of Adelaide

The team produced three new geological models: the plate model, the provincial model, and the orogeny model.

“There are 26 orogenies – the process of mountain formation – that have left their mark on today’s crust architecture. “Many of them, but not all, are related to the formation of supercontinents,” said Dr. Hasterok.

“Our work allows us to update maps of tectonic plates and the formation of continents that are in textbooks. These plate models, which are composed of topographic models and global seismicity, have not been updated since 2003.

The new board model includes several new microplates including the Mackuarie microplate located south of Tasmania and the Capricorn microplate that separates the Indian and Australian plates.

“To further enrich the model, we added more accurate information about the boundaries of deformation zones: previous models showed them as discrete areas, not as wide zones,” said Dr. Hasterok.

“The biggest changes in the plate model were in western North America, which often has a border with the Pacific plate drawn as the San Andreas and Queen Charlotte faults. But the newly drawn border is much wider, about 1,500 km, than the previously drawn narrow zone.

“The second big change is in Central Asia. The new model now includes all deformation zones north of India as the slab is bulldozed into Eurasia.

https://www.youtube.com/watch?v=N-HPPmcG-o
A story told by the continents. Credit: Dr. Derrick Hasterok, University of Adelaide

Published in a journal Earth science Commentsthe work of the team provides a more accurate view of the Earth’s architecture and has other important applications.

“Our new model for tectonic plates better explains the spatial distribution of 90 percent of earthquakes and 80 percent of volcanoes from the last two million years, while existing models cover only 65 percent of earthquakes,” said Dr. Hasterok.

“The plate model can be used to improve the geohazard risk model; the orogeny model helps to understand geodynamic systems and a better model of Earth’s evolution, and the provincial model can be used to improve mineral research. “

Reference: “New Maps of Global Geological Provinces and Tectonic Plates” by Derrick Hasteroke, Jacqueline A. Halpin, Alan S. Collins, Martin Hand, Corne Kreemer, Matthew G. Gard and Stijn Glorie, May 31, 2022. Earth science Comments.
DOI: 10.1016 / j.earscirev.2022.104069

The work included researchers from the universities of Adelaide, Tasmania, Nevada-Reno and Geoscience Australia.


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