A newly published, open access paper in Physics of the Earth and Planetary Interiors suggests that the movement of the earth’s continents will eventually grind to a halt. It’s an initially shocking statement but then very quickly makes sense. Of course plate tectonics will eventually stop; at some point the interior of the earth will cool to such an extent that it won’t be able to pull the crust along with it as it flows; indeed, the interior will stop flowing completely eventually.
The new paper, by researchers in Australia and the US, predicts that the continental plates will be forever fixed in place about 5 billion years from now, which means that we are already the best part of halfway though the total movement that our surface can expect to see.
Up until now the sheer size of the earth combined with friction and all those lovely radioactive elements down in the mantle have kept things hot enough for liquid magma to churn in the depths. This used to happen on Mars but is thought to have stopped more than a billion years ago when Mars’ core solidified, it just wasn’t large enough to sustain the heat.
I’ve tried looking for a map that would be a best guess of what the earth will look like by that time but it’s proving devilishly hard to find one. Either no scientist is willing to put their nickel down or I’m not looking in the right places. There are plenty out there put together by amateurs but I’m not going to spread those around when I can’t verify their veracity. The best I could come up with is this YouTube clip that shows the continents move as Pangea breaks apart and ends by predicting how the surface will look 100 million years from now. Don’t ask me what happens to Australia, it just seems to disappear.