Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How started Plate Tectonics on Earth?

12.11.2015

Hot mantle plume rising to the lithosphere induced the first large-scale sinking of lithospheric plates

Our planet Earth is the only planet in the Solar System that possesses Plate Tectonics. The Earth’s surface is in a constant state of change; the tectonic plates together with the oceans and continents continuously slide along one another, collide or sink into the Earth’s mantle.


View from the deep Earth of the broken outer shell of the early Earth (blue) and forming of new lithospheric plates (red) as a result of mantle plume-lithosphere interaction in a 3D numerical model. (graphics: GFZ)

However, it still remains unclear how Plate Tectonics started on Earth. An international research team combining modeling experts from the ETH Zürich, the GFZ German Research Centre for Geosciences, and geologists from the University of Texas and Korea University in Seoul have proposed an answer to this question in a recent publication in the journal Nature.

Based on advanced high-resolution numerical modeling and geological observations they demonstrate that a hot mantle plume rising to the lithosphere from the deep mantle might have broken the intact outer shell of the early Earth and induced the first large-scale sinking of lithospheric plates, a key process of Plate Tectonics called subduction.

The rigid outer shell of present-day Earth that includes crust and uppermost mantle, i.e. the lithosphere is divided into several plates. Lithospheric plates slide along their boundaries or colliding with each other and some of them, which are cold and heavy enough, sink into the deep mantle.

This process, called subduction is the key process of Plate Tectonics responsible for the recycling of the materials of Earth’s crust into the deep mantle and for an efficient cooling of the Earth interior. However, subduction and Plate Tectonics was not always taking place on Earth.

During the first 1 or 2 billion years of the 4.5 billion years Earth’s history, the tectonic process was very different, probably similar to present-day Venus, where the lithosphere is not broken into plates and no subduction occurs. So how did the first subduction and Plate Tectonics develop on Earth?

“Three conditions must have been met for the mantle plume to start first long-lived subduction and Plate Tectonics on Earth”, says Stephan Sobolev, Head of Geodynamic Modeling Section at GFZ and Professor of Geodynamics at University of Potsdam.

“First, the mantle plume had to be large and hot enough to produce a lot of melt. These melts intruded into the lithosphere above the plume making it mechanically weak and allowing the plume to penetrate into the crust. Second, the lithosphere had to be thick and heavy enough to sink into the mantle”.

In the beginning the broken lithosphere around the plume was probably pushed down by the load of the plume material spreading above it and then the sinking parts of the heavy lithosphere pulled down the adjacent lithosphere. “Finally there had to be liquid water in the ocean to lubricate, in a way, the surface of the sinking lithospheric plate” adds Sobolev. “This allowed it to sink deep into the Earth”.

All these conditions were fulfilled sometime in early Earth history, but were never met for other planets of the Solar System. For instance on Venus, which is most similar to the Earth, hot mantle plumes are probably quite common, but the lithosphere is too hot and light and there is no liquid water at the hot surface of Venus.

It was most likely not just an interaction of a single mantle plume with the early Earth lithosphere, but rather a number of such interactions that were responsible for the triggering of Plate Tectonics on Earth. The vigorous inner life of our unique planet created a number of “plate tectonic windows” as shown in the Figure, which joined after some time and induced global Plate Tectonics.

T.V. Gerya , R.J. Stern, M. Baes, S.V. Sobolev and S.A. Whattam, Plate tectonics on the Earth triggered by plume-induced subduction initiation, Nature, 12.11.2015, DOI: 10.1038/nature15752

Franz Ossing | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Further information:
http://www.gfz-potsdam.de/

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>