Updating our understanding of Earth鈥檚 architecture
New tectonic plate model with boundary zones in darker shading.听Image: Dr Derrick Hasterok, 成人大片.
New models that show how the continents were assembled are providing fresh insights into the history of the Earth and will help provide a better understanding of natural hazards like earthquakes and volcanoes.
鈥淲e looked at the current knowledge of the configuration of plate boundary zones and the past construction of the continental crust,鈥 said Dr Derrick Hasterok, Lecturer, Department of Earth Sciences, 成人大片 who led the team that produced the new models.
鈥淭he continents were assembled a few pieces at a time, a bit like a jigsaw, but each time the puzzle was finished it was cut up and reorganised to produce a new picture. Our study helps illuminate the various components so geologists can piece together the previous images.
鈥淲e found that plate boundary zones account for nearly 16 per cent of the Earth's crust and an even higher proportion, 27 per cent, of continents.鈥
鈥淥ur new model for tectonic plates better explains the spatial distribution of 90 per cent of earthquakes and 80 per cent of volcanoes from the past two million years whereas existing models only capture 65 per cent of earthquakes,鈥 Dr Derrick Hasterok, Lecturer, Department of Earth Sciences, 成人大片
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New models showing the Earth鈥檚 architecture. Video: Dr Derrick Hasterok, 成人大片.
The team produced three new geological models: a plate model, a province model and an orogeny model.
鈥淭here are 26 orogenies 鈥 the process of听mountain formation 鈥 that have left an imprint on the present-day architecture of the crust. Many of these, but not all, are related to the formation of supercontinents,鈥 said Dr Hasterok.
鈥淥ur work allows us to update maps of tectonic plates and the formation of continents that are found in classroom textbooks. These plate models which have been assembled from topographic models and global seismicity, have not been updated since 2003.鈥
The new plate model includes several new microplates including the Macquarie microplate which sits south of Tasmania and the Capricorn microplate that separates the Indian and Australian plates.
鈥淭o further enrich the model, we added more accurate information about the boundaries of deformation zones: previous models showed these as discrete areas rather than wide zones,鈥 said Dr Hasterok.
鈥淭he biggest changes to the plate model have been in western North America, which often has the boundary with the Pacific Plate drawn as the San Andreas and Queen Charlotte Faults. 听But the newly delineated boundary is much wider, approximately 1500 km, than the previously drawn narrow zone.
鈥淭he other large change is in central Asia. The new model now includes all the deformation zones north of India as the plate bulldozes its way into Eurasia.鈥
A tale told by the continents.听Video: Dr Derrick Hasterok, 成人大片.
Published in the journal , the team鈥檚 work provides a more accurate representation of the Earth鈥檚 architecture and has other important applications.
鈥淥ur new model for tectonic plates better explains the spatial distribution of 90 per cent of earthquakes and 80 per cent of volcanoes from the past two million years whereas existing models only capture 65 per cent of earthquakes,鈥 said Dr Hasterok.
鈥淭he plate model can be used to improve models of risks from geohazards; the orogeny model helps understand the geodynamic systems and better model Earth's evolution and the province model can be used to improve prospecting for minerals.鈥
The work included researchers at the Universities of Adelaide, Tasmania, Nevada-Reno, and Geoscience Australia
Media contacts:
Dr Derrick Hasterok, Lecturer, Department of Earth Sciences, The 成人大片. Mobile: +61 (0)432 247 975, Email: derrick.hasterok@adelaide.edu.au
Crispin Savage, Acting Manager, News and Media, The 成人大片. Mobile: +61 (0)481 912 465, Email: crispin.savage@adelaide.edu.au