Help with tectonics

[Steel General]

Some good progress here, even if I don't get all of the tectonic stuff.

[Karro]

Wow, thanks for your all help guys ^_^ I don't think I had that much positive reinforcement on my projects in my life You're great.

I'm currently working on refining the coastlines (they look blurry and splotchy on my original map so I'm redrawing them o_O) and trying to draw islands in place of markers, but I've looked over the forums and (unsurprisingly) found a lot of cool articles and tutorials here. I'm going through them but since I'm not that good at science in my native language, you can imagine how slow it is in Enlish... @_@

What I've done with the map I'm posting now:

1. 6 and 9 are now colliding, as are 15 and 11! Yay for London drivers smashing into each other head on! (thank you for that image, altasilvapuer )
2. 7 is moving in another direction, which I guess means islands on the collision site (thus brown triangles abound). I also changed the boundaries a bit since I wanted the islands closer to the continent.
3. Islands added: 9&10, 2&17, 16&15, 13&15
4. I hid the mountains for now since there were too many things on the map already
5. I tried to do the whole "shade plate boundaries with according to what plates do what to each other" thing altasilvapuer suggested, but only gone so far before going completely stumped o_O My problem is, I can't quite figure out some of the plates since they move under an angle that doesn't make it absolutely clear whether they, say, collide or slide near each other. For example, plate 1 slams into plate 6, but plate 6 slides past plate 1. How do you handle that? I marked the borders with mixed colors, but how does this tectonic confusion affect the above-groundy stuff? Do these borders behave like one type or the other? Is it the matter of simply what plate moves faster?

thebax2k, with the 16th plate I figured it's moving away from the 9th and and sort of away from the 14th, so I thought the ocean would be very deep there, with no islands. Am I missing something?

Karro, I haven't yet even thought about projection... I'll add more ocean to the sides to make it less square when I start coloring. It's just that it's a very big file already (the images you see are 7 percent of the size) and I didn't want to make it even bigger. As for distortion, I pasted the map onto Google Earth and it looked alright for me. Maybe that's because continents are not that close to the edge of the document. Anyway, the world is fantasy and I think I'll be going for a stylized look, so distortion won't be that much of a concern. I guess this is the place where my desire for realism gives way to my control impulses (distort something I've made? O_O make it all weird-looking and unintelligible? Oh noes! Never!)

Thank you again for all your help

Well, no worries about any weaknesses in English: A good map is a language all its own.

So, at your boundaries where one plate is slamming into another, but that plate is moving laterally, like the 1/6 boundary, you're going to get a mix of effects. Since 1 is smashing against 6, you'll probably get a convergent boundary effect - meaning that one or the other is probably slipping under the other and creating an island chain. At the same time, the transformative side of the boundary is going to mean this is an active earthquake zone.

At the same time, this could be an example of what I was talking about with different plates affecting the movement of each other. 6 isn't moving toward 1, but 1 is pushing up against 6. Given the current direction of 6's movement, and a basic understanding of what would happen if these were objects floating on water, and you'd start to see the pressures exerted on 6 would cause the bottom half to continue swinging rightward, while the top half may start to push up toward the the top or left, squeezing against that divergent boundary. at the end of the day, we might see a roughly counterclockwise turn being effected on plate 6, overall.

You're also right that with 9 and 16 being divergent boundaries, we'd expect to see a deep trench along that line, and not islands at all.

Projection might not be a prominent concern, but for me it was kind of a head-smacker later when I realized that I hadn't planned for that, and once pasted onto Google earth I got a lot of distortion on my northern continents. You're right that yours aren't too near the poles, so it may be less of a problem. I also notice that, compared to earth, your world is a little heavy on the ocean-cover and a little light on the land. This will likely have effects on the overall climate of your planet (with smaller landmasses, comparatively, you'll have better moisture distribution and fewer deserts, most likely).

[altasilvapuer]

The trick with marking the more complicated boundaries like 13/15 and 6/1 is to note that even along a single boundary, every point doesn't interact in the same way simultaneously. In the case of 13/15, the parts of those plates edges that are more or less perpendicular to the plate motion will be some form of subductive/convergent. The edges that are more or less parallel to the plate motion will tend to be transform.

I don't have any images on hand that really illustrate that well, but if the wording's not clear, let me know, and I'll cook up a quick example.
Actually, I'm going to go ahead and cook up a quick little example of what I mean. Will upload shortly.

-asp
---
Edit: Okay, here's a quick blob of (iffy at best) tectonic plates, to illustrate what i was talking about a little bit more.
Tectonic Example I.jpg
1. Here, Plates A and B are colliding slightly more dead-on than sliding against each other, so you're going to get something constructive in the plate boundaries. I threw in a continent piece for the fun of it and decided that Plate A is carrying a subcontinent that's colliding with the dge of B. You'll have some pretty big mountains at 1. and just south of it, but not quite as big as the Himalayas, because this is a little more oblique.

I guess an analogy here is a pair of cars in a collision that's almost head on, but not quite. Probably the center of one hood hitting near the corner of another.

2. Here, the plates are mostly sliding alongside each other - this is more like the yahoo who scrapes the side of a car parked in the street and takes out a wing mirror and leaves big gashes in the paint job and frame.

3. At note 3, Plates B and C are moving apart, spreading from a mid-ocean ridge. Because no part of this line that's visible lies more parallel then perpendicular to the plates' motions, I've coloured it all red. Note, however, that oceanic rifts tend to spread unevenly, so this would be a blockily-jagged line, with transform boundaries separating sections of different spread-rate sea floors. My mouse is being finicky, though, so I couldn't reliably represent that.

This is like hooking a tow truck to the front bumper of a car and a tow truck to the back bumper of the car, and telling them both to hit the gas.

4. At 4., we've got something somewhat intermediary between 1. and 2. Here, Plate A and Plate B are more or less even on whether the boundary is perpendicular or parallel to their motions, so I'd expect to see something like what Karro described earlier. Plate A I have here assumed to be riding up over the top of C, which is moving East while being subducted. In theory, this should be fully possible (and I'd assume highly volatile), but I'm honestly not sure. This, however, would be like a sedan driving East while a monster truck drives over it in a South-Southwesterly direction.

But, you should probably take all the above with a grain of salt, as I've only just recently started delving into tectonics mostly over the course of late last spring and a little this summer, and a small bit in high school, but not a lot at all, then. Still, I think it should be reasonably close enough for the purposes of creating fantasy and science fiction worlds. And besides, even the experts have under the belt the amazing research pool of a whopping...one planet. For all we know, we might all be hacks.

-asp

[Laime]

Okay, while I hammer out the tectonics I decided it was time to proceed to climate. After all, all the large landmasses are there...

I tweaked things a bit, of course - I enlarged continent C and moved a mountain range on continent B to the other side of the continent. I don't know why those mountains are there, they are just there ^_^

Rainfall map I didn't have much problem with. But with currents I'm not so sure, and, consecutively, I'm a bit wonky on the temperature zones. Did I do it right?

[altasilvapuer]

I think B's mountains are actually even pretty okay with the tectonics you had before. They might not be very tall, and I'd wager that they're creeping somewhat NE, even as they form, but they'd be there, I think.

With the ocean currents, the simplest ones to do are the surface currents. That seems to be what you're doing, but figured I'd clarify as it has come up in the past. The thermohaline system is really fudgy for me, as I haven't researched it enough, but I could help you with surface currents.

On the surface, you tend to get water cycling from warm to cold and vice versa. In the Northern Hemisphere, this cycle rotates clockwise; in the Southern, counter-clockwise (or anti-clockwise for you Brits across the pond, as I recall ).
The surface currents are also where one of my other favourite reference images comes into play. I didn't draw mine anything like this, as this image is a little too technical for all but those more patient than tectonics to draw, but it did get my understanding a pretty long way with surface currents:
http://upload.wikimedia.org/wikipedi...rderless)3.png

Warm currents tend to go up Eastern Seaboards in the Northern Hemisphere and down, and cooler currents tend to go along Western seaboards in the respectively opposite directions.

I would start with that, and a gradient based solely on latitude for temperature. Once your currents are reasonably laid out, you can drag the temperatures out of their latitude-zones based on where the currents would carry them.

-asp

[Laime]

altasilvapuer
Thanks! The tectonics stuff I think I more or less get ^_^ I just need to draw the islands now...

As for the currents, I know that it's surface mapping. For climate you don't really need anything else, or so I've read. I had no idea about warm currents going East and cold going West though. *goes off to redraw things*

[altasilvapuer]

Well, they go those directions if your planet rotates counterclockwise, I should say. I'm a little wiped today, so my brain's not 100% up to par.

The main issue is just that the cold and warm regions of water (pole & equator, basically) mix via convection, and that because the planet is rotating (in the case of Earth, anyway) counterclockwise, the coriolis effect causes them to cycle in those directions.

At least, that's the way I understand it.

-asp

[Laime]

I used the example altasilvapuer provided me to draw my own currents. Frankly, it's all I'm prepared to do in regards to this issue o_O My brain already hurts. What I'm doing now is filling in the islands and working on an approximate climate map. When I'm finished, it's elevation and rivers time! Yay! *goes away to hide under her blanket for a moment at the thought of rivers*

Alright, all done panicking now ^_^ Here are the currents.


Also, since I don't need help with tectonics anymore, the thread has a new title ^_^ "Sapere" is a codename that won't ever be used, since it's an inside joke between me and myself. It's part of Latin expression 'sapere aude' ('dare to know', imperative), that was originally used by Aristotle and then repeated by Kant. And since three primordial races of my world sort of kind of correspond to Kant's three functions of the mind (reason, creativity, morality, for those who find that kind of thing interesting) I snagged the expression and sneaked the reference into the meta-world.

Yes, I am a geek.

[Ascension]

Philosophize all you want, I'm always listening.

[Laime]

Ascension
That's... err, good to know *is paranoid* ^_^"


On a sidenote, you can't change the title of your thread. That's bad -_-