2-minute video shows 1.8 billion years of continental drift on Earth

A new study uses a combination of old models, new geophysical data and improved simulation software to reconstruct how plate tectonics has changed the shape and position of continents over the past 1.8 billion years.

Plate tectonics is a scientific theory that describes the large-scale movement of fragments of Earth's rigid outer shell on an inner stretchy layer. Driven by convection currents in the Earth's interior and plate boundaries that sink into the mantle due to gravity, Earth's tectonic plates move as fast as our fingernails grow. However, since tectonic processes on Earth began 3.3 to 3.5 billion years ago, this speed was more than enough to move entire continents across the planet.

In one of the most comprehensive models ever, a new study has summarized 1.8 billion years of plate tectonics in a two-minute video clip.

The reconstruction covers 40 percent of Earth's history, but this period includes the emergence of complex cellular life (about 1.65 billion years ago) and the formation of three supercontinents – Nuna (2.1 to 1.8 billion years ago), Rodinia (1.26 to 0.9 billion years ago) and the youngest supercontinent Pangaea (335 to 200 million years ago).

The international study, led by geophysicist Dr. Xianzhi Cao of Qingdao University in China, combined previously published maps, ages determined by mountain-building processes, the opening of tectonic basins and volcanic eruptions, with geophysical data available in recent years.

Using traces of the magnetic field preserved in iron-bearing rocks, the authors were able to reconstruct the former position of the continents. Radiometric dating of igneous and metamorphic rocks, combined with tectonic shifts, provided an accurate time frame.

Knowing how tectonic plates have moved over time helps scientists better understand how the Earth works.

Volcanic eruptions and earthquakes are directly related to the way the plates move against each other. Friction at colliding plate boundaries accumulates energy, which is eventually released in the form of a devastating earthquake. Volcanoes form primarily where the Earth's crust is deformed or breaks apart, allowing magma to rise to the surface.

The slow movements of continents determine sea levels, ocean currents and long-term climate changes. Even the evolution of life is influenced by plate tectonics. When continents break apart, land animals and plants become isolated and eventually evolve into new species.

A better understanding of plate tectonics also has practical applications. The distribution and accumulation of resources needed by our modern civilization, such as coal, oil, gas, metals and rare earths, is determined by the formation of sedimentary basins and mountain ranges when continents break apart or collide.

The full paper “The tectonic evolution of the Earth and its plate boundaries over 1.8 billion years” was published in the magazine Frontiers of geosciences and and can be found here.

Additional material and an interview with study co-author Dr. Alan S. Collins were published online by The conversation.