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/

More articles from Earth Sciences:

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

nachricht Modeling magma to find copper
13.01.2017 | Université de Genève

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Satellite-based Laser Measurement Technology against Climate Change

17.01.2017 | Machine Engineering

Studying fundamental particles in materials

17.01.2017 | Physics and Astronomy

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>