Having a look at the attached image (original at Wikipedia Hot Spot page) I noticed that all mantle plumes originating from lower mantle (in red) are under oceans. Why?
$\begingroup$
$\endgroup$
2
-
2$\begingroup$ Two comments: 1/ Afar is not (yet) under an ocean; 2/ These are hotspots, not mantle plumes. Hotspots are surface expression of mantle plumes, but not all plumes have already reached the surface. So from this figure one cannot say that all deep mantle plumes are under oceans. Some might be under land but have not yet reached the surface—thus have not yet created a hotspot. $\endgroup$– Jean-Marie PrivalCommented Oct 11, 2023 at 11:50
-
$\begingroup$ It would be nice to know what the different colors for the dots mean. I notice about half of the large red dots occur at boundaries of tectonic plates. $\endgroup$– FredCommented Oct 20, 2023 at 6:53
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
Mantle plumes are part of the movement driving plate tectonics. These movements push continental plates apart making oceans. It's not that they occur in oceans, they cause oceans. As pointed out in a comment, the Afar spot in Africa is not under an ocean, but it is causing the rift valley in Africa, which is full of lakes, which given geological time will connect and result in the continental plates separating and the remaining space filling with water.
