DEEP 'SCARS' FROM ANCIENT GEOLOGICAL EVENTS PLAY ROLE IN CURRENT EARTHQUAKES

Super-computer modeling of Earth's crust and upper-mantle suggests that ancient geologic events may have left deep 'scars' that can come to life to play a role in earthquakes, mountain formation, and other ongoing processes on our planet. These multi-million-year-old structures, situated at sites away from existing plate boundaries, may trigger changes in the structure and properties at the surface in the interior regions of continents.

The team of researchers created an evolving "virtual Earth" to explore how such geodynamic models develop under different conditions.

Using these models, the team found that different parts of the mantle below the Earth's crust may control the folding, breaking, or flowing of the Earth's crust within plates, in the form of mountain, building and seismic activity when under compression. In this way, the mantle structures dominate over shallower structures in the crust that had previously been seen as the main cause of such deformation within plates.

Most of the really big plate tectonic activity happens on the plate boundaries, like when India rammed into Asia to create the Himalayas or how the Atlantic opened to split North America from Europe. But there are lots of things we couldn't explain, like seismic activity and mountain-building away from plate boundaries in continent interiors.

The research team believes their simulations show that these mantle anomalies are generated through ancient plate tectonic processes, such as the closing of ancient oceans, and can remain hidden at sites away from normal plate boundaries until reactivation generates tectonic folding, breaking, or flowing in plate interiors.

Thanks to: sciencedaily.com