What would it take to jam a planet's tectonics? It seems that a huge rise in atmospheric temperatures would do the trick, causing continents to grind to a halt, mountains to stop growing and earthquakes to cease. On Earth, the motion of magma in the mantle pushes continental plates around on the surface, but if the magma became too hot and runny it would lose the grip needed to do this. picked by AutumnLotus 6 months ago

Geologists estimate that plate tectonics began during the Archean period, between 2.5 and 3.8 billion years ago - but they don't know what triggered it. Ancient Earth was too hot for the crust to solidify completely, and the lightest minerals would have floated to the surface over the entire planet, making the subduction of denser plate material unlikely. picked by AutumnLotus 10 months ago

Dr Chris MacLeod, from Cardiff University, said the Earth's crust appeared to be completely missing in an area thousands of kilometres across. He said it was an "open wound on the surface of the Earth", where the oceanic crust, usually 6-7km thick (3.7-4.3 miles), was simply not there. picked by Browntrout 2 years ago

Plate tectonics, the geologic process responsible for creating the Earth’s continents, mountain ranges, and ocean basins, may be an on-again, off-again affair. Scientists have assumed that the shifting of crustal plates has been slow but continuous over most of the Earth’s history, but a new study suggests that plate tectonics may have ground to a halt at least once in our planet’... read full post picked by AutumnLotus 9 months ago

As planetary mass increases, more heat is trapped and convection increases. As a result the shear stress within the crust increases too and plate thickness decreases. That means the plates are weaker and plate tectonics becomes "inevitable". picked by DrNothing 12 months ago

Our planet is changing before our eyes, and as a result, many species are living on the edge. Yet Earth has been on the edge of habitability from the beginning. New work shows that if Earth had been slightly smaller and less massive, it would not have plate tectonics-the forces that move continents and build mountains. And without plate tectonics, life might never have gained a foothold on our wor... read full post picked by AutumnLotus 9 months ago

Primordial rocks found recently in Greenland show early Earth as dynamic place, complete with the same plate tectonic processes we see today. picked by tundramonkey 2 years ago