Esfera - Plate Techtonics

[Deoridhe]

I've made an equirectangular map for a planet I'm making (thank you guys so much for all of the awesome tutorials!!) and am trying to figure out the plate techtonics. I'm having a lot of difficulty with figuring out how things can and should move. I'd love some feedback and thoughts on how the plates could or should be interacting, and if any of the plate shapes don't make sense.

[SDtylgar]

Hello,

Interesting idea, tectonic plates should help you to define where mountains should be.
And remember, moutains stop clouds, coulds do rains and rains help vegetation.
I think you have to much deserts near seas.

[Deoridhe]

Thanks for replying! Right now there aren't any deserts; the white/green/gold outline the polar to equatorial areas only; it's a short hand right now. I wanted to feel confident in my plate techtonics before adding mountains and figuring out the weather patterns.

[Charerg]

Welcome to the Guild, Deoridhe!

Plate tectonics can be very tricky to figure out (especially on a flat map), and you should probably decide how much effort you are willing to spend on it before proceeding further. The key concept with plate tectonics is the Wilson cycle, and the associated renewal of Earth's oceanic crust (there is barely any oceanic crust older than 180 million years on present-day Earth).

With that in mind, what you need to accomplish for your tectonics to make sense is to visualize or model the process of supercontinental breakup (it's probably easiest to use GPlates for this if you're willing to invest time into learning the program). If you want to try out GPlates, astrographer has a few handy tutorials for just this purpose on his blog.

It's also a good idea to thoroughly familiarize yourself with Earth's tectonic history, so check out CR Scotese's youtube channel, he has a ton of videos on past plate movements. In addition, Scotese's Atlas of Plate Tectonic Reconstructions is a recommended read (you can use a google account to access academia.edu, I believe), especially the "12 rules of Plate Tectonics" .

Other than that, offhand I might point out that having a nearly identical landmass on both poles seems somewhat unlikely.

[Deoridhe]

Ooof, those are some awesome links I hadn't run into in my searches on plate tectonics! Thanks a ton, Charerg.

[Deoridhe]

I've removed a pole, made some changes to the plates, and added some mountains and rivers. The plate lines which go down at the bottom meet around the pole; trying to get that to look right on an equirectangular map was a nightmare. I think the most helpful plate information was learning that the driving force of plate movement is the convergent movement, not the divergent. I ended up picking a few spots where the convergent movement was the most and extrapolating plausible movement from there.

Ascension's Atlas Style in Gimp was really useful for designing my mountains, even if I'm not making use of masks the way he does (it kind of breaks my brain!). I did a little modification on his colors and added a layer of brighter green for plains areas, but I'm pretty happy with it overall.

[Pixie]

"Hey, someone wanting to do tectonics..."

Maps with tentative tectonics normally catch my attention. Both because I have done it myself and love a map with proper science behind, and also because I take some enjoyment in figuring out some of these puzzles. It's a very strange hobby and rarely a person takes any pleasure in working out tectonics - around 99% give up half way and either leave things as they are and continues mapping regardless or goes silent and abandons the map. Charerg, myself and a few more weirdos are the notable exceptions. So this is the disclaimer, be warned

Here's the first blunt bit: those large clusters of huge islands don't happen. Not with the kind of subduction tectonics that goes on on Earth. Get rid of them. Until you do that, the map lacks plausibility.

On the sweet note, the NE corner of the map looks promising... here's something for you on that:

[Deoridhe]

Yeah, I've been clinging to Serenthia (the island grouping to the south) for a long time, but for realism I really do need to let it go. These continents all predate me knowing anything about plate techtonics (I was thirteen and it was pre-internet), so my attachment to them is quite irrational and very strong; whatever I can justify, I'd prefer to justify, but I'd rather things be more realistic than not.

I love your notes on Zingr (the NE continent); thank so so much for how detailed they are! I'll play around with the techtonics and mountain area, and the proto-river delta (love that idea). I think with the surrounding mountains I can justify a lot of water flow, so it's about shifting the angles of the deepest rivers. Do you think something Grand Canyon-like then partially back-filled after the end of an ice age is plausible?

Is the island chains to the north even vaguely plausible? I tried to make them semi-Indonesian-like and thought of them as a nexus of a few convergent boundaries, but I don't know how well I did.

[Pixie]

Yeah, I've been clinging to Serenthia (the island grouping to the south) for a long time, but for realism I really do need to let it go. These continents all predate me knowing anything about plate techtonics (I was thirteen and it was pre-internet), so my attachment to them is quite irrational and very strong; whatever I can justify, I'd prefer to justify, but I'd rather things be more realistic than not.

I totally understand that.. I've been working te on world I started around that age as well, and it's always a pain to balance plausibility with respect for the original stuff. It will never get easier

I love your notes on Zingr (the NE continent); thank so so much for how detailed they are! I'll play around with the techtonics and mountain area, and the proto-river delta (love that idea). I think with the surrounding mountains I can justify a lot of water flow, so it's about shifting the angles of the deepest rivers. Do you think something Grand Canyon-like then partially back-filled after the end of an ice age is plausible?

Is the island chains to the north even vaguely plausible? I tried to make them semi-Indonesian-like and thought of them as a nexus of a few convergent boundaries, but I don't know how well I did.

I was going to say that passive margins normally don't have high mountains, but then I remembered the coast close to Rio de Janeiro and the entire southern portion of the brazilian coast. I guess you could have some very ancient fjords/mountains, but, then again, it would be filled with sediment and be just strange valleys. But you can't have a canyon that used to be a delta - river deltas are created by the deposition of sediment, which is the opposite of carving sediment away to make a canyon.

Large island chains and always plausible, but they need to be a) chains and b) explained by the tectonics.

[Deoridhe]

Taking the Zingr Comments and running with them, I reworked the global tectonics and resulting mountains. I tried to account for all of the inland seas and fiddly bits, and I'm a lot happier with the mountains this time. I haven't added rivers yet; I'm letting the mountains settle for a few days before I see if I want to rework them again (I think I may need more mountains at several of the convergent points) and to see if the plate tectonics hold up to second and third looks.

And obviously I reworked the island chains... though I think the Thyslin one might be a bit too chainy now. Serenthia has become a continent; it took a few redoings before I found something I was pleased with, and I tried to work off of shapes found in neighboring continents to make it seem like they had pulled apart plausibly.

Also, the delta at the southern end of Zingr has become an estuary. A large estuary, but an estuary none the less. I spent a lot of time staring at the Pearl River Bay/Estuary and a few other estuaries and deltas before making the changes, and I think they look plausablish.