Depends on the location. Activity along the Gakkel ridge could explain it. With the speed the magnetic poles have been moving (especially the north) a lot could be happening in the Arctic Ocean that is just coming to the surface so to speak. Same with the West Antarctic rift system. The problems with both are the fact that the areas are so difficult to observe. There also has been a dramatic shift in the direction/speed of the movement of the tectonic plates over the last decade. I'm not really surprised by that considering all the other factors involved.
Remember that the core of the planet consists of predominantly molten iron & nickel. What happens when you move a magnet around a pile of iron filings suspended in a liquid? You get the picture.