# Thread: WIP- unnamed fantasy world

1. ## WIP- unnamed fantasy world

So I'm redoing my map starting with plate tectonics. While looking at the plate tectonics of earth I'm having difficulty understanding how exactly the plate move in relation to the north and south poles. Looking at the tectonic map of earth Flash Presentation it seems there are two plates at the north pole. However I am uncertain if there are two or one, due to earth being a sphere it would seem that it is one. If there is just one does that mean that the plate rotates around the polar axis with a possible slight drifting in one direction? looking at the south pole it seems that the Antarctic plate is actually rotating around the south pole axis.

Any thoughts?

Thanks Ascanius

2. Hi there.

Plates movement has pratically no relation to the location of either poles and the fact that the north pole is nearly shared between two large plates is a simple coincidence (to the best of my knowledge).
(this page also has a very good illustration of Earth's plates, as seen from the north pole)

3. Excellent resource Pixie!

4. Thanks for the info Pixie. It was exactly what I needed.

5. I'll just post what I have tectonic wise here instead of creating another thread.

[IMG][/IMG]

Continental crust is brown
oceanic crust is teal.

Transform boundaries are green (non directional)
Divergent boundaries are Red.
Convergent are blue, the arrow shows which is being pushed up.

Black arrows show the net direction of the crust movement.
White arrows show the rotational direction, clockwise or counter clockwise. The dot roughly shows the axis of rotation. I did this mostly because I couldn't figure out the type of boundaries (convergent or transform) of certain areas. I remember reading the plates have a rotation so I added the rotation to clear up certain areas, I used the overall direction for the vast majority though.

On plate number 7 The idea is a rift valley formation.
The area 4,9,10 is the same idea.
Also the general direction of plate 7 is incorrect the arrow should be pointing to the north, north west.
Plate 14 has a clockwise rotation.

Anyone see any areas or anything I did wrong?

6. Your north pole seems to have no less than 5 different plates all meeting in a single spot - remember that on a 3D globe the axial poles are nothing but two points, whereas on a rectangular 2D projection they become stretched into lines (the top and bottom edges of the map).

7. Thank you for pointing that out. Looks like I have to go back to the drawing board. I'm going to cut it down to two at the poles I think.

8. Something I like to do as a sanity check is to draw my gross features on an actual globe prior to making a projected map. You can get a styrofoam sphere from a hobby store or check the ball bin at a Wal-Mart for something in a solid light color, or even simply a balloon.

It's difficult to free-hand a projection from that, of course, but it's at least a starting point to see if what you're doing makes any kind of physical sense.

Or you could use a digital 3d paint solution. I'm not sure what's out there at the consumer level, though. I have access to all sorts of cool CG animation software like ZBrush, so I've never bothered to see if something like Sketchup lets you paint on geometry.

9. Since you are at it... and since you have represented the Euler poles for every plate. I think you need to note that not every "spreading pole" is located within the plate - I think most, and specially for large plates, are outside the plate... see this pic.

10. ascanius, I'm checking this thread with interest, as I'm working on the tectonics for my world map, but I haven't grasped the hang of it yet like you seem to have done. To check how the plates meet on the poles I'd recommend what was recommended to me, NASA's G. Projector, is free, simple, and it does what you need to check the plates and poles for distortion in Orthographic projection, though I think it needs the image of your map you load to be equirectangular, as the program first loads the map in such projection.

Pixie, that pic you linked on the last post confuses me, does it suggest that two plates can share a single Euler pole?