WIP World Map

[Charerg]

eckert- World types of plates with hotspots.png
I don't know about all that stuff Pixie linked. Looks like it says a lot of meaningful things. The way I do it is like I described before, just by reasoning out how it would act if it was all bits of floaty material on a giant ball of water that was spinning. I imagine that along the equator the plates would have in general the most mass and speed and that they'd be moving in the opposite direction (relatively) to the spinning of the earth (really they'd just be rotating slightly slower, but it's not important). So those plates along the equator are going to be driving the rest of my system. If a plate has an edge along the equator plate like Plate A there it might start to rotate around it's pivot. So while it's general movement would be mostly to the east, the back (eastern) part of northern edge will be pushing north, and the western part of the southern edge will be pushing south. Whilst at the same time the front (western) part of the northern edge will be moving away from the northern neighbor and vise versa for the south.

Remember that if a plate is big enough that it is on the equator and also extend over the higher or lower latitudes this in and of itself may cause it to want to rotate.

I don't think you got to get these things perfect, you just got to get them to a level where they can reasonably be said to make sense.

As far as I know the "spin component" in plate movements is essentially nonexistant, though I can only speculate why that is the case. Possibly the crust as a whole is too much of a solid, inert object for the Coriolis force to have an effect?

There seems to be a prior thread about this in the guild, actually. Apparently there does seem to be a slight westward trend in the direction of present day tectonic plates, but it's unclear if it's caused by the Coriolis force or just coincidence.

An old post by Chick over in that thread offers a pretty good explanation (I think so, anyway):

Yes, theoretically it does, but on a scale so small as to be undetectable, and completely overwhelmed by other factors.

Consider your bathtub drain, a common example for Coriolis Effect. Theoretically, the water will always swirl going down the drain in the same direction (depending on which hemisphere you are in), but in practice it you watch and record it, the water will swirl left 50% of the time and right 50% of the time on average. Why? Because other factors such as movements in the water, even bubbles in the drain, affect it more strongly than the Coriolis Effect does.

Another common question is whether rivers are affected by CE. Rivers do not tend to flow more westward because of CE even on very flat land, because the terrain they flow through overwhelms any CE. Rivers do, however, tend to flow more heavily toward the westward side when constrained by heavy terrain, so that in mountain passes, most of the erosion is on the west side. On flat land, where the river meanders, the meandering goes both directions because the softer terrain lets the flow overwhelm any CE.