# Mapmaking Discussion & Philosophy (WIP/Critique) > Regional/World Mapping >  Mapping an Earthlike planet

## Akubra

Hi there! A few days ago I discovered the Cartographer's Guild, and being a map enthusiast (just to avoid the term _map freak_  :Wink: ), I thought "Why not join?" So I did and started reading this extremely interesting forum.

Quite some years ago I created an imaginary Australia-sized continent somewhere in the Pacific Ocean (actually it resided somewhere in my head, but you get the point). This was before computers became mainstream devices. I remember buying large A1 sheets of thick paper to pencil in sections of this continent, named Taboran (the etymology of that name is lost in the mists of my youth). Things evolved and one continent became too restricting. Much later another idea arose: at some point in the future Earth became inhabitable and if our species wanted to live on we had to search for another Earth-like planet. Several huge, autonomous spaceships were built, capable of transporting thousands of people, together with myriads of animal and plant species. Generations came and went and at some point the fleet encountered an exoplanet that looked almost exactly like Earth. After the necessary scientific tests to see if the planet was habitable the first humans set foot on Rautah.

Rautah has almost the same dimensions as Earth and orbits a star comparable to the sun. There are continents and oceans, just like we know them here. My work on it is quite limited, in fact the only thing I have is a general equirectangular map showing the sizes and positions of the continents:



Here's an adaptation of the same map, done with NASA's G.Projector (Winkel Tripel overlaid with Earth's continents):



And this is a series of hemispheres (azimuthal equal-area projection, East - West - North - South):

   

I am hoping to create a series of atlas/topographic-style maps (or one huge map) keeping up with the discoveries of the future space travellers exploring the planet. In time, they will build cities to live in and some sort of communication system (probably more advanced than roads, railways and airports). They might create administrative/political divisions, protected areas, etc.

Starting from what I have now I'd like to set up a topography of the landmasses, and see how the ocean currents flow. I think that is needed to determine a rough layout of the climate zones.

But first a few questions:

1. Any comments on the size, shape and position of the continents? What about the coastlines? I've managed to fit all the land in one supersized pan-Rautah continent (like Pangaea on Earth), so that the current shapes can be attributed to plate tectonics. Looking at the southern hemisphere however, I'm not sure about the southern part of Ghaon jutting out straight towards the South Pole. And the northern tip of Eneaga looks a bit too pointy too (see northern hemisphere map).

2. What would be a good way to add a (random?) plausible topography? The idea is to make a general map with land coloured according to height (like <100m - <200m - <500m - <1000m - <2000m - <5000m - >5000m).

3. Until now I used Inkscape because I like working with scalable vectors. My original map measures 10000 x 5000px (3.65 MB). Adding more information will make it too big to handle. I would like to have a general map where I could zoom in to areas with more detail. I read about Viewing Dale in this forum. Would that be a good choice to use for this project? Does it work with layers too? (So that I could use the same map to show natural features and political divisions by switching on/off the appropriate layers.)

4. Any ideas how I could calculate each continent's area?

This has already become a very long first post, so I'll leave it at that for the moment. Thanks for having read this far!

Cheers, Akubra

----------


## Pixie

Welcome. There are a few around working on the same kind of project that you want (have already) to embark on, at different stages of completion.

So far, your start is awesome. I really like the shapes - diverse in aspect and size. However, I agree with you, the ortographic views of the poles have show Eneage and Ghaon (specially Ghaon) awkwardly tipping towards the pole.
If you search in this, part of the forum you will find plenty of threads devoted to figuring out plausible tectonics, plausible climates, based on the planets being "created". The next step (shall we call it the standard procedure) is to give some thought to the tectonic movements that are forming those oceans and continents.

As for your main question about map size and file size: make several copies of the original land/sea file. One will be used for tectonics/topography, one for climate issues, one for political. These three topics, at least, will already yield many many layers.
One piece of advice though - it will take time to get something really nice and the majority does not get their stuff finished. The thrill is the ride, actually, so... enjoy.

----------


## Akubra

Hi Pixie and thank you for your reply.

Indeed, I should give more thought to plate tectonics. Being able to puzzle the landmasses into one huge supercontinent doesn't mean that it all fits like it should. I really should delve a bit deeper into the subject. Thanks for reminding me.

Oh, I started reading your post about ocean currents and climate. Fascinating stuff! I'll definitely need it when I get to that point.

Cheers, Akubra

----------


## Akubra

Today I worked a bit on the shapes of some of the continents:

- Flattening the northern part of Eneaga a bit made it jut out less towards the North. The resulting bump is still going straight to the North, but it is much less obvious and I like it a lot better. 
- I widened Ghaon substantially to get rid of the "bony finger" pointing towards the South Pole. Then I moved it a bit closer to Ranineo, the continent to the northeast. I like the shape of the sea between the two continents and the strait opening in the gulf to the southeast of it.
- When looking at the Southern Hemisphere I didn't like the small continent of Lohoni being so long and thin, especially the central and southern parts. So I narrowed the north-south axis a little and widened the east-west axis. I think it looks somewhat better now.

This is the current situation:

  

Next step is trying to figure out how plate tectonics could work...

----------


## jbgibson

Welcome, Akubra.  Map content in the very first post - that's worth rep right there.  And then some interesting geography and apt questions...

If you put a map in an equal-area projection you can use a simple trick in several graphics packages to get areas.  I think serif PhotoPlus, Adobe Photoshop, and the Gimp can all tell you distribution of #pixels of this color or that-- set it to two color and you have an easy calculation for percentage land.  Simple geometry gets you the overall globe surface, unless yours is oblate like Earth is instead of spherical .  Then color one continent, lake, nation, whatever at a time, and you can get its size in pixels, with a short leap to size in square kilometers or acres or what-have-you.  Make sense?

----------


## Akubra

Hi jbgibson, thanks for your welcome and your answer to my question.

Yes, your explanation definitely makes sense. My base map is an equirectangular vector map made in Inkscape. Even though Inkscape lets me measure areas, the map projection is unfit for that purpose. Somehow I didn't make the leap to transform it to an equal-area projection. I have the Gimp on my computer, but I don't use it that much. I'll have a look at it to see how I can get some results.

Thanks again for the hint!

Cheers, Akubra

----------


## groovey

To calculate continents' areas I use this mini-tutorial: Using Photoshop to easily compute surface area - RC Groups, there it's used for other purposes, but the concept is the same. The idea is the same as jbgibson commented, but explained with more detail. Of course, it was created for Photoshop, but it can't be too hard to do the same in GIMP, as the steps are very basic I think. Of course, I didn't have in mind the projection of the map and how that distorts "reality"... because I hadn't thought of it.

----------


## Akubra

Thanks for the link, groovey. Seems like an interesting alternative to jbgibsons method. I'm not sure yet if it will be applicable to the map, but it's definitely good to know another way to calculate areas.

Cheers, Akubra

----------


## Akubra

OK, it's tectonic time. I prepared a map visualizing Rautah's 18 tectonic plates based on this Wikipedia map. The symbols and colours are more or less the same:

- Arrows with numbers: plate direction and velocity with respect to East Nohhon (mm./year)
- Red lines: continental rift boundaries / oceanic spreading ridges
- Green lines: continental/oceanic transform faults
- Blue lines: continental/oceanic convergent boundaries
- Purple triangles: subduction zones



I'm currently only concentrating on the plates and their movements. In a later phase I'll fill in the resulting islands/mountains/...

All comments are welcome. Does this map represent a plausible situation? Are there any inconsistencies? Flagrant mistakes? Did I overlook something crucial?

Thanks for having a look! Cheers, Akubra

----------


## Pixie

Very good!

first the little negative: I can't quite get what's going on north of Daia plate and I'm not sure I buy Ghatia plate - I think it should have broken into an east moving east half and a western moving west half long ago... 

now, all the positives: 
- awesome job, really awesome. 
- It seems to me you first drawn it all in equirectangular projection and then re-projected. Is that right? Secondly, and what blows my minds the most is how you did those lines, not hand-painted I guess.. so, how? Please share the technique.
- the choice of colors and labels are fine, don't touch them again
- I really like Samar plate
- I really like how you use relative velocity to show the movement, I might steal that (among other things)
- the map you referred is also my base reference.

----------


## Akubra

Hi Pixie and thanks a lot for the comments!

Now for your questions:

*Daia Plate*
Now that I look at it again, I realize that there is indeed something strange going on. Daia Plate is moving eastwards at 68 mm./year while West Nohhon Plate is moving to the southeast at exactly half that speed (34 mm./year). So if their common border has an angle of about 45° they should more or less slide along each other and create a transform fault instead of a subduction zone. On the other hand, I like that subduction zone, and I think it could work if I change their relative velocities: 58 for Daia (-10) and 44 for West Nohhon (+10). I don't think it would create problems with the surrounding plate borders. Do you?

*Ghatia Plate*
I don't quite understand why Ghatia Plate would have broken in two. Ranineo Plate is colliding with it (and moving over it) in a southwesterly direction at three times Ghatia's speed. Eneaga Plate does the same from the northwest, but moves beneath Ghatia instead of over it. So these two big plates add momentum to the southwestern movement of Ghatia. It in turn has room to follow in the wake of Taiunta because that plate moves faster than Ghatia. The only convergent boundary is with Ghaon Plate in the south. Could you maybe offer a little explanation why Ghatia would have split?

*The lines*
Yes I first drew the plates on an equirectangular projection, because that is what I have in Inkscape. As for the lines, I first drew coarse outlines of the plates' shapes. Then I drew some straight lines in different colours, lengths and directions (a sort of palette) and copy/pasted them where I wanted them on the map, roughly following the outlines. For the subduction zones I grouped a line and 2 triangles. Then I deleted the outlines. I have to admit that sometimes it was not obvious what type of boundary I should use, but I think I worked it out relatively well.

Glad you liked the colours and labels!

Well, I "stole" the idea of using relative velocity from the Wikipedia map...

Cheers - Akubra

----------


## ascanius

Huuraayy for nerds, we make the worlds go round.

I agree with Pixie.  Awesome map.

----------


## Akubra

> Huuraayy for nerds, we make the worlds go round.


We do indeed, ascanius, we do indeed  :Wink: 

Cheers  - Akubra

----------


## groovey

I share the enthusiasm for the tectonic map, it's awesome. I love how natural the shapes of the plates feel, and how neat and polished the whole thing is with all the information. That tectonic map of Earth you link as a reference is also my main reference map, but gee, I could never get mine to look so good as said map AND yours. It must have been a lot of work, but it paid off.

Potential silly question: how do you decide the speed of a plate? Kind of randomly depending on your needs or is it a mathematical matter?

----------


## Triskelli

One thing I'm always curious about is how artists go about deciding where extinct faultlines and associated ancient mountain ranges might belong, such as the Appalachians in America or the Ural mountains in Russia.

----------


## Akubra

Hey all, thanks a lot for the positive input! I didn't realize the map was _that_ good  :Wink:  Anyway, it feels good when something succeeds well. Now it's time to filter out the small (and maybe not so small) mistakes I made, and then start mapping the islands and the topography of the continents.

@groovey: Not a silly question at all! Indeed, I chose it rather randomly, and adapted it where it really created problems. So, nothing mathematical involved.

@Triskelli: Good question, I'd like to know that too, because right now I don't have a clue...

Cheers - Akubra

----------


## Triskelli

> @Triskelli: Good question, I'd like to know that too, because right now I don't have a clue...


Well, after a little research, I suppose you could go about doing that by scattering a handful of cratons in the middle of the current plates and adding mountain ranges on trailing edges or where cratons might of collided in the past.  Though considering the tectonics you've got set up the centers of most of the continents already have active plate boundaries in the middle I suppose this might set itself up as a number of island chains?

----------


## Pixie

This tectonics things is both absorbing and tiring, I wonder how long how many of us will keep digging for greater realism... Having said this, welcome to the pot, Triskelli, and thanks for the read you suggest about cratons - it took me to a few maps I didn't know, including this lovely detail of intra-plate rifting (the sort of thing that makes our work on plate movement more complex and at the same time less constrained).

Now, back into Akubra map.
*Daia plate:* Chanisi plate sinks under Daia plate and this one under West Nohhon. This gives the relative age of that oceanic crust, as it is always the oldest that gets underneath. So, Chanisi is the oldest and West Nohhon the youngest. But... Daia plate is being formed as the rift is active (west boundary), so it couldn't really be older than the West Nohhon oceanic bit. I guess it can be resolved in two ways - one, change the direction of the arrows, or make that part of the West Nohhon plate an extension of the continental crust (even if submerged). ... just some thoughts.

*Ghatia plate:* Oceanic crust subduction is a major pull force that makes plates move. Because there is subduction both at east and west borders, the plate would be stretched towards both sides, like a rubber band. If you want to keep that as it is, I'd reckon central Ghatia would be the very thinest crust, with volcanoes outcropping just because magma is so close to the surface and with lots (or at least a few) local north-south rifts, and, over a few millions, it will really rupture.

As always, feel free to ignore my "perfectionism", I know this is your creation, not mine.

----------


## Akubra

@Triskelli: Thanks for the link to the craton article. Fascinating stuff! I'm not yet sure I will delve very deep into it for the map, though. I would like to make some headway and if I linger too long in the tectonic phase, I'm afraid it will become rather tedious.

@Pixie: Thanks a lot for your explanations. I see what you mean about Ghatia plate, and I can follow your explanation on Daia plate up to a point (but that's not a problem, I'll try to read up on it). I will probably change something, but I haven't decided yet how I will make it work (well, at least try to).

In the meantime I started creating island arcs along the subduction zones. The first one is the longest one, starting at Yirral plate and going all the way to the top of Onuskia plate. As the planet Rautah has more or less the same size as Earth, this is one huge arc - I haven't measured it yet, but I suspect it to be over 5 times the length of the Indonesian islands. It does look a bit weird on the map, I'll admit that. I'll post an updated map when the outlines of these island arcs are ready.

Cheers - Akubra

----------


## Akubra

Well it's time for an update (even if it's Saturday evening  :Smile: )

What has happened? Well, here are two maps (one showing the islands in relation to the tectonic fault lines and one without the tectonic stuff)

 
I got rid of the subduction zone between Daia and West Nohhon plates and changed it to a divergent boundary with sufficient transform areas (I suppose it is safe to do so because Daia moves much faster than West Nohhon at a sufficiently wide angle). I also widened Daia and the southeastern part of West Nohhon, to bring the subduction zone northwest of Tabinoth closer to that continent, which I find visually more appealing.I'm still wondering if I should do something about Ghatia plate. Ghatia's western fault line is not pulling it underneath Eneaga plate, but rather the opposite: Eneaga is pulled underneath Ghatia. So the pulling force is coming from the east, where Ghatia is going underneath Ranineo plate. For the moment I think I'll leave it as it is.Then I started with the island arcs near the subduction zones.
There is one extremely long subduction zone starting at Yirral plate and going all the way to the north of Onuskia plate. I tried not to overdo it by placing a few long, thin islands along the fault line and filling some other areas with smaller islands. I think the result is still a bit weird, but maybe that's just because there is no such long arc on Earth, so I'm not used to seeing it.I like the positions of the islands around Ranineo. They seem to flow quite nicely around the continent.I chose to place two bigger islands north of Yirral, and again sprinkle them sparsely around Tabinoth.

So, what do you think? Does it have a sufficient level of realism? Is it visually appealing? Don't hold your horses!  :Smile: 

Cheers - Akubra

----------


## Akubra

OK, let's see what Rautah's ocean currents have in store.

I prepared two maps. The first one shows just the continents and ocean currents. The second one is somewhat cluttered with a few big red "egg-like features" showing the areas I'm not sure about.

But first this: to avoid things to become too complicated, I placed the equatorial counter currents at 0°, the equatorial currents at 10° N/S, and the currents on their opposing sides (the ones that make the gyre circles complete) at 50° N/S. Rautah has the same rotation/spin as the Earth, with a comparable tilt and duration. I didn't take into account the coriolis effect (you'll see that some of the currents have long straight lines). Re-reading this makes me wonder if I didn't make it too uncomplicated...

Anyway, here are the maps (and the inevitable questions):

 

[See the red egg labeled A on the map] Is this current possible? It seems weird because it is going clockwise while all other gyres go anticlockwise. If it should go anticlockwise too the incoming and outgoing currents will cross, and that doesn't feel right either. Or perhaps it should not make a loop, but continue southward and squeeze itself through the strait connecting it with the ocean around the South Pole. I suspect this strait is between 100 and 150 km wide. Is that wide enough to let a major current through? Which brings me to another question: is the northern strait wide enough (it's about 1000 km wide) to let both the incoming and outgoing currents pass? If not, should there be a separate circular current in area A, disconnected from all other currents? Or maybe none at all? To be honest, I'm quite confused about that area.[See egg B] Is it possible for an equatorial counter current to pass through these straits and feed one of the southern gyres?[See eggs C1 to C6] As I don't have any continent at the poles, could the northern and southern gyres connect through currents flowing near the poles, as drawn?Any other issues that seem impossible?


Thanks for having a look!

Cheers - Akubra

----------


## groovey

It's VERY visually appealing, even without terrain, just as it is now. I longingly stare at it for a while each time I stumble upon it. 

Forgot if I told you, but I love the land masses, and the quantity and placement of the islands looks really natural to me. I love your long chain of islands around the central area of the map, they'd be so useful for early migrations and exploration purposes.


I'll be checking your work on the ocean currents with interest, as I did with Pixie's, as I hope someday to get the hang of it, but I'm afraid I won't be able to give you any input on that, because it's like Chinese to me. I guess that's the "bad" side of being too science nerdy as we try to be with our maps, not too many fellow guild members will know enough about it to help others.

Let me end telling you I really like how neat and polished your technique for everything is, the land masses, the tectonic map, now the currents... it's not as simple as you make it seem to get such appealing visuals.

----------


## Pixie

... very nice.

I'm on a tight schedule, so I'll quickly try to answer your "egg-questions", (as much as I can)

A: I think it should swirl the other way around. Surface currents are wind-driven, mostly. Winds at the bottom of that area are westerlies (east-bound), winds at the top of that area are equatorial (west-bound). I'd say the water gets sucked into that closed area from the cold current on the west coast of the continent.

B: I have no clue but, personally, I would have drawn it the other way around.

C: You forgot the polar circulation (same direction as equatorial circulation, roughly at 60/70 degrees) - that will solve all your problems.

----------


## AlexSchacher

Ill give you my opinion on these but i am no expert.

1. I would either leave it as it is, or make it have its own secluded circular counterclockwise current. I definately wouldnt try to cross tge currents as it wouldnt make much sense, and i wouldnt see a current squeezing its way through that small strait to the south either. I would assume that you wouldnt even have a continental shelf drop in that strait anyways.

2. I see no reason why it wouldnt, as the current is moving forcefully in that direction and theres nothing in the way to stop it, seems to make sense to me.

3. I would assume those currents are fine aswell,  as they are up againdt one landmass most of the time just like your other currents. Not so different from earths north pole current i think.

----------


## Akubra

Thanks a lot for all this positive input! To me this is also an important motivation to improve on the maps.

@groovey: Thanks a lot for all the praise, but let me tell you that I can be a bit of a pedant and a nit-picker in some areas!  :Frown:  Even if those traits are not looked upon very favourably most of the times, they do have their merits, as they help me to work with an eye for detail somewhat above average.  :Smile:  It's probably this nit-picking that shows in my maps... 

@Pixie: Thanks a lot too for replying even when you don't have much time. I really appreciate it  :Smile:  (but never feel obliged to respond to my questions). I think I'm going with all your suggestions. If the current is entering area A by making a bend around the small continent then the direction of rotation will be the same as the main gyres. Now that you mention it, it does seem more natural to have the current in area B go the other way. And of course I'll include both polar circulations and see how it influences the rest. I didn't draw them because I was unsure how I had to position them, having no continent to circle around.

@AlexSchacher: Thanks for your input too, Alex. Indeed, crossing currents felt completely wrong. I'm still working on the continental shelves (should have done that first, before starting with the currents), and indeed, the continental shelf will connect the large and small landmasses there. Oh, and great I could borrow your arrows idea!

As soon as I have the continental shelf and the updated currents map ready, I'll post them.

Cheers - Akubra

----------


## Akubra

Time for some updated maps.

The first is a slightly adapted tectonic map, this time also showing continental shelves.

The second one is an update of my ocean currents map, also with continental shelves. I think I included all of Pixie's suggestions. The main changes are:
The inclusion of a north and south polar current (I hope I have my arrows right...)The reversal of the current between Nohhon, the big continent in the west and Tabinoth, the island/continent to its south.The reversal of the current between Ranineo and Ghaon, the two big continents in the east.
I can't help feeling that it looks like one giant waterslide.  :Smile: 

 

Feel free to comment, wether you like the maps or think they're rubbish.

Cheers - Akubra

----------


## Pixie

I have only positives to say. I really like the outcome of your work on this, and it looks like, climate wise, it's ready for the next step. Pretty impressive worldbuilding so far  :Very Happy:

----------


## groovey

Pretty impressive, I agree, and it's happening so fast for you, you might be the first of us to be finished at this rate.

One silly thing though, is it only me or the new tectonic map posted it's a bit blurry? Specially on the green lines. Is it because of the change of projection? No biggie though, just curious.

----------


## Akubra

Thanks Pixie and groovey!

Yes, I too like the overall results I've been able to produce this far. Not that some things can't be improved, though!

@Pixie: Indeed, the next one will be a climate map. Strangely I feel more daunted to tackle that than the previous maps. I'll see how it turns out... I'm sure Geoff's Climate Cookbook will come in very handy!

@groovey: Yes, I'm not very happy with the shades/crispness on these maps either. I'm not sure what it is, but I suspect it has something to do with the layers. When I used G.Projector to produce a Winkel Tripel projection, as I normally do, the results were even worse. That's why I uploaded the equirectangular maps I work on. As for the speed I'm working at, that has something to do with the amount of free time I currently have. It won't always be like that, I assure you!  :Frown: 

Cheers - Akubra

----------


## groovey

Just noticed, again in the tectonic map with the continental shelves, that when subduction happens on oceanic boundaries, you actually had in mind the trenches that are created on the side getting subducted, so you leave said side as deep ocean, and even when no islands have met the surface yet on those subduction zones, you indicate the shelves. I love that, really, really nice detail that I need to keep in mind when I do my selves.

----------


## Akubra

Thanks groovey! There are also some areas that can be improved though, such as the subduction zone east of Eneaga, the northern continent in the centre. The subduction zone starts near the base of the peninsula pointing eastwards. I think the continental shelf should be hugging the peninsula's coast more than it does now. And maybe I should add a little shelf south of the subduction zone too. Right now it looks just the opposite of what it should be.

Cheers - Akubra

----------


## Akubra

OK, here's another update, and a rather long one.

1. *What's an 'Earthlike planet'?*
A few days ago I was thinking: "When I talk abaut Rautah I want to be more precise than saying it's an 'Earthlike planet'." So I sat down, did some research, started calculating and after a few hours came up with these numbers:

Radius (eq.): 	7 353 km							(1.154 times Earth) (I'm not yet sure about the polar radius)Equator length: 46 199 km							(1.153 E)Area: 			679 384 087 km²						(1.332 E) (calculated for a perfect sphere)
Tropics: 		22° 09' 19.6" [22.155°]				(a little south of Earth's tropics)Polar circles: 	67° 50' 40.4" [67.845°]				(a little north of Earth's polar circles)
Volume:			1.665 x 10^12 km					(1.537 E)Mass:			7.677 x 10^24 kg					(1.285 E)Density:		4.611 g/cm³							(0.836 E) (less than Earth to compensate for its larger volume and still have a comparable surface gravity)Gravity:		9.477 m/s²							(0.967 E)
Length of day:	24h 19m 11s [24.320 Earth hours]	(1.013 E)
If you spot any inconsistencies or outright impossibilities, feel free to point them out.

2. *Tectonics revisited*
When I saw Pixie's latest tectonics map I told him I was jealous.  :Smile:  So I had another look at mine. I thought it was OK, but I also wanted to have some more _interesting_ areas. Of course I didn't want to imitate Pixie, but his map made me try a few things with mine. The result is below. I added a few smaller plates, broke up some others and made some adjustments to their movements and the continental shelves. Be my guest to comment. I just hope I didn't make a mess of it...



3. *Taboran revisited*
In my very first post on CG I told about Taboran, the very first continent I had imagined. I was almost certain that somewhere I still had a crude drawing of it on graph paper. So I started searching in some boxes that were tucked away in hard-to-reach corners. It didn't even take too long before I could exclaim: "Lo and behold!" I quickly scanned it and gave Taboran a place on the planet Rautah. I downgraded it to an island, because its original size as a continent would have been too large to fit. You can find it on the eastern boundary of the eponimously named tectonic plate (one of the new plates). The island is created by Taboran plate colliding into Yirral plate. It does feel good to finally find a place for it  :Smile: 

4. *Windswept*
I started with the preparations for a climate map, but it's going quite slowly, as I expected. I've come as far as the maps with the dominant winds. I'm not going to say too much about it, but let you judge. The first one is for the Northern winter / Southern summer (January), the second one for the Northern summer / Southern winter (July). On these maps the polar fronts and the ITCZ are straight lines (for the time being).

 

Thanks for having reached this point of my rant  :Wink: 

Cheers - Akubra

[EDIT] I realize I haven't taken into account mountain ranges in the maps with the dominant winds. I have prepared a crude mountain ranges map which I will post tomorrow.

----------


## Pixie

Well, I'd like to say welcome to Taboran first. My childhood world also started with a smaller piece of land, it was a large island called Brania, so I totally relate.

Secondly, I like the way you strive for perfectionism. Each version is a thoughtful improvement on the previous one. Your changes and microplates did not make a mess. Yet, tectonics plausibility there's two details you are failing to address (I was too until recently):
- if you have the divergent boundary in an ocean unsymmetrical you normally explain the missing crust on one side with subduction (like pacific ridge vs. south america) - Akua plate you can get away as it is rather small, but for the boundaries east and west of Nohhon... hmm...
- when you change the curvature of oceanic subduction, you are changing which side is sinking

(alas, these details have no influence on the land masses or location of mountains, so - as always - you can choose to ignore them)

It seems like your weather maps are having (will have) more work done on them, so I'll wait for corrected versions - in the meanwhile, let me say that  your H/L centers are visually very appealing.

----------


## Akubra

> I like the way you strive for perfectionism. Each version is a thoughtful improvement on the previous one.


Thanks Pixie!




> if you have the divergent boundary in an ocean unsymmetrical you normally explain the missing crust on one side with subduction (like pacific ridge vs. south america) - Akua plate you can get away as it is rather small, but for the boundaries east and west of Nohhon... hmm...


I understand. So what you are saying is that I should either change the location of the boundary, i.e. more towards the centre of the ocean, or change the nature of the boundary (which means changing the direction and/or velocity of the plates)? I'll see what I can do about it.




> when you change the curvature of oceanic subduction, you are changing which side is sinking


I'll check my subduction zones against their counterparts on Earth.

Meanwhile, as promised yesterday, here is a rough outline of the mountain zones I'd like to have:



Blue: mountains being created by convergent boundaries
Red: volcanic zones (on land) created by divergent boundaries
Black: mountains created by past plate collisions (it looks like I have created a lot of coastal mountains...)

Cheers - Akubra

----------


## groovey

And I thought your tectonic map couldn't get better! But damn it did.

----------


## Akubra

Thanks a lot groovey! (Still got some work to do if you read Pixie's comment above... but hey, that's part of the deal).

Cheers - Akubra

----------


## Akubra

It's been a few days since my last post (been busy with other things).

I've tried to take into account Pixie's comments about tectonics and made the following changes:

The boundary between East Nohhon and Eneaga plates has moved to the west, so that it lies more central in the ocean between the two continents.The boundary between Onuskia and East Nohhon plates has disappeared. I've created a new plate (Nohali) between the two of them. Nohali's western boundary lies roughly in the centre of the ocean between Ranineo and Nohhon. The southern portion of its eastern boundary is the same as the eastern boundary of Otia, a microplate that has disappeared. The northern portion is a new subduction zone creating a few islands to its east. I've managed not to perturb the existing ocean currents by these islands.Akua's western boundary is now more to the east, and I've created a new microplate (Sayali) lying between East Nohhon, Taikaram, Akua and Taboran plates.I don't know what to do about Pixie's second remark (changing the curvature of oceanic subduction). Where would the direction of subduction be wrong on this map?


Unless it contains something completely illogical, I'd like to leave the tectonic map roughly as it is now (save for a few minor corrections that can be done quickly).

I've also slightly adapted the position of Rautah's main mountain chains (blue = mountain building at convergent plates, red = volcanic activity at divergent plates, black = existing old mountain chains from previous tectonic activity). I'm going to take these mountains into account to create my dominant winds and climate maps. I don't think I will have the patience to puzzle them together like I did with the tectonics and ocean currents maps. I'm satisfied with an acceptable climate map without hot deserts at the poles or sea level ice fields at the equator  :Wink: .



Cheers - Akubra

----------


## groovey

Hello!

Seems most of us have gotten busy with other things lately! I hope to get back in track soon.

Anyway, what I think Pixie meant, because he's helped me with that on my map, is that on subduction boundaries, the side "eating" the other plate would usually have a convex oval shape, with the triangles pointing towards that side "eating" the other. Explaining it with words sometimes makes it more confusing, but well. For example, on your last tectonic map, the subduction boundary btw Eneaga and Sulina, Gathia and Taiunta plates; from Eneaga's point of view, the boundary has an "outward" or convex oval shape, so Eneaga should be "eating" Sulina and friends and the triangles should point the other way around.

That is, of course, if I didn't understand wrong, so I'd wait for confirmation from other more reliable sources.

The second image with the "outline" for mountains and volcanic activity is cool. I'll do something like that once I'm done with the tectonics (I'm very close), but adding seismic activity in yellow (if I'm able to spot it). Since the current orogeny and the volcanic activity are mostly determined by the tectonic map, there isn't much room for you to improvise or for us spot "mistakes". I do have two questions:

1. So it's assumed that where there are islands' chains of obvious volcanic origin there's also volcanic activity so it's not indicated, or you simply didn't need that info represented, just when it's from divergency?

2. Thankfully we are free to place old mountain ranges where we please, as long as it's not highly implausible, but one thing that catches my attention is you hardly have any of the old ones inland, they are mostly coastal. Not that there's anything wrong with that, but I'm just curious about it. For me it's a practical issue because I'll need many rivers to place settlements, and for example, in your Ranineo continent, they would have to rely in small mountain ranges and rainfall for "steady" water sources (like in the island I'm from before bottled water was a thing, we have no rivers here, and lack of water was a constant historical worry for thousands of years), perhaps just visible in regional maps, wouldn't they? Because rivers created by the old coastal mountains on your map would look for the easiest way to the coast. Or how would you solve the lack of big rivers inland in that continent? This is probably not something you are interested in anyway, but have you given any thought to it? I'm truly interested.

----------


## Akubra

Hi groovey, and thanks for your post. Sorry it took me a few days to respond.

I checked your explanation about the convex/concave subduction boundaries against a tectonic map of the Earth. Not surprisingly, I'm quite convinced that you are right. Thanks a lot for pointing that out! For some reason I missed seeing that. It also means that I should change some boundaries and island chains. Hopefully that will be the last major change.

Now your questions:

1. I could give you many reasons why I didn't indicate the volcanic activity caused by subduction... But the simple truth is, I just forgot it...  :Embarassed:  I started with the divergent boundaries and then went on with the older mountains, missing the subduction boundaries entirely. Good that you spotted it!

2. The map's many coastal mountains are indeed something that's bothering me too. I don't exactly know why, but when choosing mountainous areas I feel drawn to the coasts. Maybe it's because of their shape: I seem to place the mountain chains on long peninsulas and long stretches of more or less straight coasts; somehow they feel natural there (not sure if that's true in reality). I really should give more thought to placing a few of them more to the centre of continents. As for your observation that _rivers created by the old coastal mountains on your map would look for the easiest way to the coast_, well, you're right of course, but the way a river is heading all depends on where it originates. Take the Amazon, which is one of the major rivers in the world. Its source lies much closer to the Pacific Ocean than to the Atlantic, yet it crosses the breadth of South America and discharges in the Atlantic, creating the enormous Amazon Basin and the most expansive rainforest in the world. True, its source is located in the Andes, which is not an old mountain range, but I think it would still be possible if the Andes were much older. That said, I do agree that I should have some mountains away from the coasts. If anything, it would make things more interesting.

Cheers - Akubra

----------


## Pixie

Hi folks.

Good thing groovey managed to explain to you how convex/concave works when subduction happens between oceanic plates. Looking at your map, I second you in identifying that as the single change that needs (needs is always a strong word...) to be done. Mainly at the boundaries between Eneaga and Sulina and between Eneaga and Yirral, but you could also revise the boundaries between Ranineo and Lomo.

Other than that, I'd be very happy with the result of your work.

----------


## Akubra

Thanks Pixie. I'm planning to make one more major revision (I know it'll never be really final, of course) to correct these things, and then it's about time to move on. The climate map is still waiting. I've been postponing it for some time now. Hopefully I'll find the courage to continue working on it in the coming days.

Cheers - Akubra

----------


## Akubra

I finally managed to get my tectonics done. I tried to be as complete and correct as possible. These are the boundaries I reworked:

The southern and northwestern boundaries of Tabinoth plateThe boundary between Eneaga and Yirral platesThe boundary between Eneaga and Sulina / Ghatia / Taiunta plates (with the long island arc)The boundary between Ranineo and Otaia / Ghaon / Arumanthi platesThe boundary between Lomo and Ranineo / Arumanthi plates
In order to get the direction of subduction right I created a few additional small plates:

Agehoni and Utoni plates (off Eneaga)Sira plate (off Ranineo)
I also broke off two other plates off Eneaga (Rantaia and Irumi plates) to create a new subduction zone between it and East Nohhon plate and some volcanic activity in the west of the continent. In the process I also moved the continent of Eneaga slightly to the northwest.

I checked, double-checked and triple-checked the plates, boundaries and motions, and I cannot find anything substantially wrong with them. I hope you cannot either  :Wink: . Here's the new tectonics map:



These important changes in Rautah's tectonics meant that I also had to rework the ocean currents. This is the new version:



Of course, all comments are welcome. I think I will let tectonics and ocean currents rest for a while now and concentrate on wind, rainfall and climate. See how that goes...

Cheers - Akubra

----------


## ascanius

The only thing I noticed is Sayali plate looks like it should be going in the opposite direction away from the divergent boundary.  Other than that it looks good.  I really like the southwest region a lot.  Overall I think you did a very good job.  Keep up the great work.

----------


## Pixie

Well, I was about to write that everything looked perfect... then I read the post by ascanius. Yep, that looks like it should have the arrow pointing opposite.

As for the rest, yes, it is perfect to my eye. Ready for the next step. Word of advice: you will need some for of heightmap, but don't get over detailed as that is a task to take ages. Set just 4 or 5 different levels of altitude - it will be enough.

----------


## Akubra

@ ascanius: Thanks for spotting that! I have corrected my mistake on the local map on my computer. It's just a small update, so for the moment I'm not going to upload that version here. Yes, the southwest region does look promising, doesn't it (even though it also looks quite complicated...)

@ Pixie: Thanks for the advice! Right now I'm working on a rough height map, and I'm really into it now. Before posting the climate map, I'll post that height map, to be sure I can use it as a base for the climate map. I'm really wondering what that will look like!

Cheers - Akubra

----------


## groovey

Congrats Akubra, on being done with your tectonics. What a relieve it must be. Glad that you can move on too, and looking forward to see your take on a height-map.

----------


## Akubra

Hi folks, during the past few days I have been working on a height map as a preparation for a climate map. It's meant to be a purely functional map - its sole purpose is to get information across.

There are 6 height levels: 1 shade of green, 4 shades of grey and white. These are the altitude ranges they indicate:
- green: < 1500 m.
- darkest grey : 1500 - 3000 m.
- next lighter grey : 3000 - 4500 m.
- next lighter grey : 4500 - 6000 m.
- next lighter grey : 6000 - 7500 m.
- white : > 7500 m.

I imagine the highest point of the planet to be slightly higher than 10000 m. above sea level.

To make it a little clearer, here are two maps: one showing the tectonic plate boundaries over the altitude shades and one without the tectonics.

 

A few questions:
- Do you see any inconsistencies between the tectonics and the mountains/ranges/plateaus formed by them?
- What about the locations and heights of mountains/ranges/plateaus formed by earlier tectonic forces (i.e. those away from the current tectonic boundaries)? In general I have made them lower and with a gentler slope to indicate their age.
- What about the amount of ranges, their sizes and the areas occupied by the different altitudes? Too little, too much, or about the right amount/size?
- I wasn't sure what to do with divergent boundaries on land. I added small, low to medium heighth volcanic ranges (not higher than 4500 m. in general) and mostly elongated lakes. Is that the way to go?
- Any other issues I didn't consider?

I may still add 2 or 3 islands on divergent boundaries located in oceans. These islands will be about the size of Iceland or smaller and their high points will not be over 3000 m.

I'll slowly start drawing the rain patterns based on this map, and hopefully I won't have to correct too much.

Thanks for your feedback!

Cheers - Akubra

----------


## groovey

As usual, I'm afraid I can't give expert input. Actually, I'm looking forward to hear what the others have to say about it so I can learn a thing or two, because I'd love to do a similar thing for mine. 

I do find the system to convey the altitude info useful and clear.

Since the colors indicate altitudes and not simply mountains, they look alright to me.

I know the map is just for info for the climate map, so you'd think about this sort of thing then, but did you have in mind the tropics/subtropics when placing old mountain ranges/altitude, since said tropics are prone in Earth to be kind of desertic and so have a lot of erosion, I ask as a noob, I'm not sure if that's something you have to worry about?


What was your logic for placing the old mountain ranges? Were they simply placed randomly where they fit or you wanted them to be? This is how I do it but I'm not sure if there are rules about it.

The big lake on the top left, how did it came to be? Not by a current divergent boundary, so is it explained by tectonics? By the "closing" of one land bit against another in the past, or how?

----------


## Akubra

Thanks for your input groovey.

Some answers for you:
No, I didn't take into account the latitude when placing mountains. Like you, I don't know if I should. You have a point when saying that deserts erode mountains (wind and sand), but I suspect other latitudes have other kinds of erosion (water, ice expanding). So does one kind of erosion go faster than the other? No idea.I placed the old mountain ranges rather randomly where I thought it would be nice to have mountains. The only aspect I took into account was the distance between the coast and the continental shelf (for coastal mountains): if they were close together I gave the mountains a steep slope, if they were far apart I gave them a gentler slope.Ah, the big lake! I had to have a really, really big lake - bigger than the Caspian Sea. The problem was where to put it. I figured that it could be placed where it was surrounded by high mountains and/or large plateaus with lots of rivers running off them (especially off the huge plateau to the lake's east). The lake would be in a depression with slightly higher land to its north and with an outlet to the ocean in the west. But, as always, my logic may be flawed...  :Wink: 
Cheers - Akubra

----------


## Pixie

, 
Hi Akubra.

Here's some input. I'm using your questions to organize the points.




> A few questions:
> - Do you see any inconsistencies between the tectonics and the mountains/ranges/plateaus formed by them?


I'd prolong the land in the boundary between Sira and Lomo plates. That mountain range would be prolonged southwards, creating a peninsula, and a north-south oriented range, in tune with the boundary.





> - What about the locations and heights of mountains/ranges/plateaus formed by earlier tectonic forces (i.e. those away from the current tectonic boundaries)? In general I have made them lower and with a gentler slope to indicate their age.


Fine, mostly. The only one I think less plausible is the coastal range in Arumanthi. That looks like an old plate (even its oceanic crust is old), so the range would have eroded - that sediment runs to the coast, making it wider and the continental shelf in there should also be wide.




> - What about the amount of ranges, their sizes and the areas occupied by the different altitudes? Too little, too much, or about the right amount/size?


This is the detail you still need to work on (in my humble opinion!).
In this you made a mistake I was also making in my early elevation maps. You have way too much land above 2000/3000 m. Have a look at his map - its choice of colors really makes the land above 3500 m stand out. On Earth, extreme highand happens much less than in your world. Old ranges have been eroded so much that they hardly reach the 3000m and they would also be very irregular in shape.




> - I wasn't sure what to do with divergent boundaries on land. I added small, low to medium heighth volcanic ranges (not higher than 4500 m. in general) and mostly elongated lakes. Is that the way to go?


The lakes between Ghaon and Yama would be in elevated land. Whenever you get a divergent boundary inland, the rise of magma forces the ground to lift. If you look at Earth, the great rift in Africa is surrounded by highlands.





> I may still add 2 or 3 islands on divergent boundaries located in oceans. These islands will be about the size of Iceland or smaller and their high points will not be over 3000 m.


Go ahead. I can sea some oceanic islands in Taikaram and Akua plates being great for early navigators/explorers.

----------


## Akubra

Thanks a lot, Pixie, for those valuable answers (as always!) I'll see how I can adapt the map.

I'm really anxious to start the climate maps, having read through your tutorial based on Geoff's Cookbook. It's really well devised and I'm sure it will be a huge help. Must have been (and still is, I notice) a lot of work. Anyway, I'm eager to see what sort of climate my landmasses will end up with.

Cheers - Akubra

----------


## ascanius

Hey Akubra.  I took a look at your height map and I think it works very well.  The only thing that really caught my attention is the Tibetan plateau like range in the western continent.  Now if your going for something like the Tibetan plateau it seems that that range should be wider and spread more along the length of the range instead of narrow and extruding from the range.  Take a look at that height map of earth pixie posted and take a look at the Tibetan plateau to see what I mean.  This all assuming that area is formed by the same process.

Oh and nice to see your working towards doing a climate map.

Keep up the work and good luck.

----------


## Pixie

I agree with ascanius 100%. You either make that area an old plateau (meaning you lower it) or you make it more north-south oriented.

----------


## Akubra

Thanks a lot to all for the feedback!

I have adapted the map according to the suggestions of Pixie and ascanius. For easier comparison with the map Pixie mentioned (this one) I also modified the colours for the different elevation ranges.
- blue: < 1500 m.
- light blue : 1500 - 3000 m.
- green : 3000 - 4500 m.
- yellow : 4500 - 6000 m.
- orange : 6000 - 7500 m.
- red : > 7500 m.



These are the changes I made:




> I'd prolong the land in the boundary between Sira and Lomo plates.


Done. It was a good idea to create a peninsula on the inside of Sira, instead of the islands I had there. The southern tip of those mountains ending in a bay were indeed a bit awkward.




> The only one I think less plausible is the coastal range in Arumanthi.


Good point. I tried different things with it, but in the end I just deleted it, because nothing ended up the way I liked. I did widen the continental shelf and created some islands on it.




> You have way too much land above 2000/3000 m.


I was afraid it would turn out that way. Depending on the mountain range I worked on I did one or more of the following things to fix this:
- Flattening ranges by removing an elevation colour and lowering the next ones up (if there were any)
- Making old ranges smaller by a given percentage or redrawing parts as to have them cover a smaller area
- Placing old ranges farther from the coast than their original position. (I know this doesn't lower the land, but it creates a smoother topography more in line with the erosion forces)




> The lakes between Ghaon and Yama would be in elevated land. Whenever you get a divergent boundary inland, the rise of magma forces the ground to lift. If you look at Earth, the great rift in Africa is surrounded by highlands.


They would be indeed, but their surface elevation would probably not be higher than 1500 m., which places them within my lowest elevation range (blue). I checked the African Rift Valley lakes and all the main ones lie under 1500 m. There are lakes that are higher, but they are smaller (a few 10s to a few 100s of km²). The smallest lake that you can distinguish on my map has an area of several 1000s of km². I did change this zone a bit by creating more elevated land over 1500 m. alongside and in between the lakes.




> I can sea some oceanic islands in Taikaram and Akua plates being great for early navigators/explorers.


I did place one there. Two other islands lie between East Nohhon and Eneaga and on the tripoint where Onuskia, Lomo and Nohali meet. I'm not yet sure if I will *have* early navigators/explorers in the traditional sense. I'm envisaging Rautah to be discovered and colonized by future space-travelling humans from Earth, and they will have far more advanced technology than seafarers we have known on our planet. But as said, all that is not yet written in stone. The way it goes could be completely different...




> Now if your going for something like the Tibetan plateau it seems that that range should be wider and spread more along the length of the range instead of narrow and extruding from the range.





> You either make that area an old plateau (meaning you lower it) or you make it more north-south oriented.


I was wondering about that plateau too. I didn't know if it could exist in that shape or not. You're both right of course. But it's a bit of a dilemma for me. On the one hand I want a very large plateau, and on the other hand I want it to be high. So I decided to have a bit of both by downsizing the high eastern half and make it more elongated and lowering the western half to make it some sort of extention of the old northern range. Would that be a possible solution?

Like I said in one of my previous posts, I would like to have a huge lake too. I placed it in that area because I figured it could have formed in a depression and function as a catchment area for the many rivers coming from the plateau and the range to its west. Would such a lake be plausible? And would it be able to have a big river carrying its outflow to the ocean?

Cheers - Akubra

----------


## Pixie

As a working heightmap for climates, I think this is good enough. You solved the weird bits so there's nothing now that screams implausible. As for the position of the lake. I can see the tectonics for a depression there (the rising coast east shuts down the area from its original drain system). I'm afraid, though, it might be placed at desert latitude... you'll have to find out.  :Wink: 

As for the lakes in the rift - I meant that you should raise the land around the rift, not the lakes themselves.
Like this:

----------


## groovey

Good work Akubra, your experience with the height-map will be really useful and a reference to me to do mine.

You seem to be done with the currents, what about the winds? Are those in page 4 definitive or will you rework them now that you have the height-map?

Edits: just saw on ascanius thread you said you're not done with the winds yet, so I got my answer.

Also, when assigning colors to the different altitude levels, how did you decide how many levels to have and what range in meters each would have? 

Could this classification system work as well?

0-1.000m
1.000-2.500m
2.500-5.000m
5.000-7.500m
>7.500m

----------


## ascanius

Hey Akubra the new height map looks good.  With regards to the plateau it works fine the way it is.  You could still do it the way you had it height wise it just needed to be elongated more north and south was the only problem.  Looking forward to seeing the next step.

----------


## Akubra

Thanks for the comments, guys!

*@Pixie:*



> As for the position of the lake. I can see the tectonics for a depression there (the rising coast east shuts down the area from its original drain system). I'm afraid, though, it might be placed at desert latitude... you'll have to find out.


Now that I look at the latitude I have placed it at, I think you're right. If it turns out to be a desert there I'll have to move the lake elsewhere.




> As for the lakes in the rift - I meant that you should raise the land around the rift, not the lakes themselves.


Thanks for the diagram. I'll have another look at how I want the divergent zones to look like in the height map.

*@groovey:*



> Also, when assigning colors to the different altitude levels, how did you decide how many levels to have and what range in meters each would have?


Since I made the height map as a base map for the climatic maps I didn't go into too much detail. In one of the posts above Pixie confirmed that that wasn't needed. On Wikipedia I read that the lower end of a cumulonimbus cloud (raincloud) reaches about 2000 m. in height, so I figured that all land under 1500 m. could be susceptible to rain and the land between 1500 m. and 3000 m. partially. That's why I chose elevation ranges of 1500 m., which gives me 6 ranges. I picture my planet having a maximum elevation of around 10000 m. but I didn't include a 7th range (> 9000 m.), because the area of it would be extremely small.




> Could this classification system work as well?
> 
> 0-1.000m
> 1.000-2.500m
> 2.500-5.000m
> 5.000-7.500m
> >7.500m


If you use your height map for the same purposes as I am, I don't see why not. As long as you take into account the amount of wind and rain that is possible at the various altitudes, then I think your system should be ok. 

*@ascanius:*



> With regards to the plateau it works fine the way it is.  You could still do it the way you had it height wise it just needed to be elongated more north and south was the only problem.


I think I like it the way it is now. I might tweak it a little, but I just have to see how everything works out climatewise.

*General note:*
I will not have much time to work on my project next week (I might write a short post or two, but not much). The week after that may be a little less busy. I don't think I will be able to do anything in the first half of August. So any serious work will have to wait until next month...

Cheers - Akubra

----------


## Pixie

Enjoy your holidays, Akubra  :Wink:

----------


## Akubra

Thanks Pixie (you're partly right, of course  :Wink: )

I've been skimming through some of the threads here. Seems like I will have a lot of catching up to do later on.  :Confused:  But it does look very interesting (I wouldn't have expected anything else!  :Smile: )

Cheers - Akubra

----------


## Akubra

Real life has a way of interfering with my online presence (I'm sure that's the case for everyone). Almost 2 months ago I was planning/hoping to be back online by mid-August. Now the end of September has arrived and I still haven't been able to contribute a post, let alone work on my project. Nothing bad has happened, just different things in real life leaving me very little opportunity to continue my activities here on CG. I have no idea when I will be able to resume where I left off. Next week? Next month? I can't say. But let me assure you, the project isn't dead. It's just forced to take an extended rest. The moment a few things change again, I'll be back working on it, discussing it with you guys, as well as giving my humble input to your own projects. Hope to be back soon!

Cheers - Akubra

----------


## groovey

I hope you're back soon Akubra, I feel really lonely here with the 3 of you gone. But I'm very glad to hear if you're not around it's not because of bad things.

----------


## Akubra

Hi folks,

Hope you're all well and thriving!

A month or so ago I woke up from my hibernation to find that the world (this one, that is) was still turning and that the middle of summer had arrived. So, I had a good look at my maps and started working on my own world again. One day it should be turning too.

I took up where I left off all those months ago: rain patterns, temperature and climate. I mainly followed Pixie's tutorial and went through all the steps up to 7. A lot of work, especially step 7.

I'm including the result: 2 rain maps (northern summer/ northern winter), 2 temperature maps (again northern summer/ northern winter), and a climate map.

Rain maps: the colours go from light to dark blue in 6 steps (dry - low - moderate - wet - very wet - extremely wet).
Temperature maps: the colours from low to high temperature are: dark blue (extremely cold) - pale blue (very cold) - green (cold) - yellow (mild) - orange (warm) - red (hot) - dark red (very hot).
Climate map: I used the same colours as in this map (one exception: I used only one colour for Dfc/Dsc/Dwc). White areas mean that no climate has been found for that area.

What do you think of the climate map? As said, I haven't yet done step 8, but as it stands now, is it basically realistic?Apart from Dfc/Dsc/Dwc there were no results for climate type D. Is this plausible?I added a few steps for the mountains: starting from 1000m, I made the temperature one level colder for each 750 m higher. Otherwise I would have ended up with a mild temperature at 5000 m and above near the equator. Not very realistic.Other observations?

Rain maps (northern summer/winter):

 

Temperature maps (northern summer/winter):

 

Climate map (sorry for the white lines!):



Hey, it's nice to have written something here again. Hope I can keep working on this planet for the coming months...

Cheers, Akubra

----------


## groovey

Long time no see! Glad to hear from you again slacker! And you're back with a bang. I mean I have no idea if there are any mistakes in the maps you posted, because I have no criteria for the climate stuff, though myself will try it soon too.

So I'll be sure to pay attention when the experts do share their input.

----------


## Deadshade

The precipitation map doesn't seem very realistic.
It is hard to comment on climate when latitudes are not shown. I suppose that you had them but then forgot to show them on your maps. So my comments stay rather general.

What is immediately striking is that your precipitation maps show a circular symetry on continents.
This never happens. On the contrary the atmospheric circulation is always asymmetric and depends on latitude - it is either the westerlies or the easterlies that dominate.
For example if your planet rotates like the Earth then you'll have dominating westerlies in the temperate northern zone. From that follows that the western edges of continents will be much wetter than eastern edges.
This asymmetry is especially important if there are N/S mountain ranges. These will create a very strong rain shadow on the eastern side and very high precipitations on the western side (think Vancouver climate which is defined by that dynamics).

For the temperatures. 
T depends on altitude in a pretty linear way - on the Earth it is in average about - 7°C/km . A bit more if air is very dry and a bit less when air is very humid.
That means that a 5 k high mountain in tropics will have 30 °C at foot  and - 5°C on the summit. This difference will stay the same in winter and in summer.
Also, on the contrary to precipitations, the temperature distribution is more regular and symmetric. Temperature is basically distributed in latitudinal bands (e.g the average temperature only depends on latitude) with a large discontinuity between oceans and continents. 
This is due to the fact that the amplitude of oceanic temperature variations is much smaller than the ampltude of continental variations. It is this difference which creates seasonnal monsoon regimes on approppriate places.

For the details about the atmospheric and oceanic dynamics, you may have a look at the tutorial : http://www.cartographersguild.com/sh...ad.php?t=30482

----------


## Akubra

Hey groovey, it sure is good to be back! Looking forward to working on these maps again and learning stuff from all you guys.

Thanks Deadshade for your explanation. It does indeed make a lot of sense.

This planet has indeed the same direction of rotation as Earth's and it is comparable in size (slightly larger). I do have a few N/S mountain ranges. There's even one very close to the coast, in the far west of Nohhon, the largest continent. The southern part of it should be under the influence of the Northeast Trade Winds, so I might have a rain shadow on the western side (even if not very pronounced).

I'm tempted to try your approach to the subject and see what climate/biome map it results in. I'll keep you posted.

And next time I'll try not to forget to show latitudes...

Cheers - Akubra

[edit] mixed up east/west. Shame on me!  :Mad:

----------


## Pixie

My method, as posted, is messed up from step 7 onwards. If you read through my discussions with Azelor, or his discussions with Deadshade in while I was absent, you can pick this up.

I have since improved it and used it personally in Maward (with improvements), but as Azelor is taking the lead on this one, I'm letting him lay down a path we can all try to follow.

As for your maps, I totally agree with Deadshade - the East-West simmetry of each continent, mainly in terms of rain, is definitely an indication that something was miscalculated at some point.

----------


## Akubra

Hi Pixie, yeah, now it's quite obvious to me too that something went wrong. I'd better read threads till the end in the future.

Anyway, I don't consider the work to be for nothing. I've changed from Inkscape to Gimp, and it gave me the opportunity to learn and gain some experience with Gimp.

Cheers - Akubra

----------


## Deadshade

> . I've changed from Inkscape to Gimp, and it gave me the opportunity to learn and gain some experience with Gimp.
> 
> Cheers - Akubra


That's a great victory ! 
I wish that something would make me go in the reverse direction because I suspect that Inkscape could help me doing some things that are more difficult/cumbersome in Gimp.
But I never had the opportunity for Learning that sofar  :Wink:

----------


## Akubra

Thanks Deadshade!

I'm certain that for a number of cartography tasks Inkscape would lend itself quite well, and it's not too hard to learn (at least the things I did with it weren't too difficult...  :Very Happy: ).

When starting to build my planet I chose it because it is a vector graphics editor. I thought that it would allow me to go into as much detail as I wanted, but after some time the program started to get slower because of memory problems―for my planet maps I had thousands and thousands of points defined along Bezier curves―until it finally crashed a few times and became unworkable.

At one point in the future I hope to make some topographic maps with contour lines. They would cover only a small section of my world. Perhaps Inkscape is better suited to those kind of maps. I'll have to look into it when the time comes.

Cheers - Akubra

----------


## derik999

Awesome maps Akubra, extremely helpful!

----------


## Akubra

Thanks derik999, glad you liked them. Hope your writing and mapmaking are going smoothly!
Cheers - Akubra

----------


## derik999

> Thanks derik999, glad you liked them. Hope your writing and mapmaking are going smoothly!
> Cheers - Akubra


Thank Akubra, I appreciate it! Figuring out climates during the year is an element that I haven't taken into consideration when drawing the rough outlines of my current map. The more realistic the better. Same goes with topography. It's a fantasy world so of course I can get away with some stuff but when realism can be applied then why not?

----------


## Azélor

I  see a couple of problems with the maps you posted.

The variation of temperature with altitude are not ok. The summits are often too cold, especially in winter. Very few places on Earth have temperature below 0 in their hot season. Outside of the high central Greenland (covers 80% of the island), most of Antarctica and some Canadian islands with mountains in the Arctic, only the high mountaintops have an average temperature below 0. 

95% of Tibet is slightly hotter than that in summer, it's a tundra. Same thing in the Andes with a city like La Paz (average temperature always close to 10 degrees) https://en.wikipedia.org/wiki/La_Paz
I'm not sure what the ration altitude/temperature should be but I know that high humidity tends to limit the effect of elevation. 
A thinner atmosphere mean a drastic variation in temperature, making high mountains on the poles have greater temperature variations. (can someone confirm this?)



About the temperature: some general rules.

Yes, the biggest factor is the latitude: places hit directly by the light from the Sun will be hotter that those receiving it at an angle. But it does not tell us why Ireland is hotter than Newfoundland or why Asia is generally colder than America at the same latitude or why the east coast are sometimes much colder than the west coasts.

Other important factors:

1-Temperature of the currents: apparently, the water does not contribute in much of the temperature difference. Because the air/winds have a larger impact on changing the temperatures. Therefore, the Gulf stream has little influence on New England and Eastern Canada because the winds are blowing to the east pushing the warm air to Europe (but a large portion is probably lost in the sea)

Humboldt current is probably one of the coldest on Earth, Chili's cost is also colder than the other west coasts.
California current is cold, it's just mild and help tempering the extremes. It's influence is only limited to the coast tough. 
Benguela current is also cold but not as cold as Humbolt probably because of it's medling with a hot current: Aguihas. 
The Labrador current is much colder than the Kamchatka current because it receive a lot more of cold water directly from the Arctic. 
And so on.  

2- Actually China is Colder than the USA only in winter but it's hotter in summer. The differences are even more extreme in Central Asia around Kazakhstan. The 2 reasons are often linked. A large landmass far from the water at high latitude can become very cold. If the winds are blowing from the sea like in Eastern Europe (Belarus, Ukraine, Western Russia), it will limit that impact. but if the winds are blowing from already cold places, it's likely to make the air even colder as in China. China is actually cold in winter compared to other places at the same latitudes, I noticed that only 1 or 2 days ago!

more later

----------


## Akubra

> The more realistic the better. Same goes with topography. It's a fantasy world so of course I can get away with some stuff but when realism can be applied then why not?


Derik, if you want to go the "realistic way" you might be interested to read these threads:

This is a thread in which Azelor is trying to find "climate rules" on Earth and apply them to a fictional planet.This, this and this are other threads which try to follow plausible rules from tectonics to ocean currents to climate. 

Hope you find something to your taste!

Cheers - Akubra

----------


## Akubra

Azelor, thanks a lot for the long explanations.




> Very few places on Earth have  temperature below 0 in their hot season. Outside of the high central  Greenland (covers 80% of the island), most of Antarctica and some  Canadian islands with mountains in the Arctic, only the high  mountaintops have an average temperature below 0.


Ok, so  something that I should keep in mind. On the other hand, some of my  mountain ranges are very, very high, even higher than Everest. A good  example is the N/S oriented range in the middle of Nohhon, the large  continent in the west. This is where two enormous plates collide and  it results in the highest mountain range on the planet, over 10,000 m high.  To the west of it lies a large plateau sloping down gradually from 5000  m. I can imagine that temperatures in the higher regions of that range  never go over 0°C.




> I'm not sure what the ration altitude/temperature should be but I know  that high humidity tends to limit the effect of elevation.


This  is a Wikipedia article about it. According to it a rule of thumb is 10°C/km in  relatively dry air and 5.5C°/km in saturated air. But apparently it can  vary a bit with other factors. This confirms what you say about  humidity. So that would mean that on the rainshadow side of a mountain  range it should be colder at a certain height than at the same height on  the other side of the range.

You make interesting observations about the difference between water  and air, regarding their impact on temperature. If I understand this  correctly, ocean currents and wind direction should be handled together  then, and currents would have an effect on nearby land if the wind is  blowing in the direction of the land. If not, its effect would be  negligible.

Looking forward to other discoveries!

Cheers - Akubra

----------


## Azélor

This is the article: http://www.americanscientist.org/iss...mild-climate/1

Basically, it says that the winds would be blowing differently if North America had no mountains chain to disturb it. As the air moves over the Rockies, it gets compressed and shifts south to keep to momentum because of the force of Coriolis? Personally, I'm not entirely sure it would have such a great impact. The thing is that, without mountains, the warmer air from the North Pacific would reach further inland, more like in Europe but maybe not as hot. This would probably lower the pressure center of the continent but NA would still be colder because the maritime influence has it's limits. Europe is a fairly small continent surrounded by water. So yes, the Gulf stream does not heat NA much. Also, the impact of the winds form the Gulf stream on Europe is marginal in summer when the temperature of the water are usually lower than overland.   


Yes about the humidity/effect on temperature based on elevation but it gets very complicated to apply on a created world, on top on all the other things. 


The other problem on you map has to do with subpolar oceanic currents. Unless the latitude is very high, the winds should blow from west to east like this : http://www.learn-eo.org/lessons/l6/i...a_ice_map2.jpg
maybe above 75 or 80.

----------


## Akubra

> The other problem on you map has to do with subpolar oceanic currents. Unless the latitude is very high, the winds should blow from west to east like this : http://www.learn-eo.org/lessons/l6/img/l6_sea_ice_map2.jpg maybe above 75 or 80.


And I thought that my currents map was ok. Not so, it seems.  :Frown: 

Well, I am starting to think that on the one hand all this is very interesting and absorbing, but on the other hand where does it lead to in relation to what we're trying to achieve here? My goal is to have a believable climate map. It doesn't mean that everything must be explainable. I'm not sure how deep you want to delve into this and to what level of accuracy you want to go. It's a fact that the inner workings of Earth's climate still withhold big chunks of unexplained matter from us. And I wonder, if we don't understand our own planet's climate well, how can we discover the rules to which the climate of an imaginary planet would obey?

So I think I'm going to be a bit more pragmatic about it and try to find a way to carve up my planet into the most plausibe climatic zones I'm capable of. The thing is, right now I don't really know where to start. Have you read Deadshade's tutorial about Realistic CLIMATE DESIGN for cartography? I'm tempted to give it a go, perhaps a little less general and taking into account some of my planet's peculiarities where I can. I'm going to think this over for a while...

Cheers - Akubra

----------


## Azélor

Well, the last thing about oceanic circulation seemed pretty important. I know I go into a lot of detail but it's important that  understand the little details in order to come with a simpler system. Sometimes a lot of these details are irrelevant but unless you have an idea of the whole picture, who can't realize they are. 

No we don't understand all the climate on Earth. I don't delve into thermohaline circulation or El Nino because their impact of the climate and why they form is not fully understood. Maybe the thermohaline makes the Brazil current weaker than the Gulf stream but it does not seems to have any meaningful impact ...

I just need to go into a lot of details to eventually be able to explain it simply with a model.

----------


## Akubra

Thanks for your explanation, Azelor. It makes a lot of sense.  :Smile: 

I had the impression that you were trying to build a fine-tuned climate model consisting of a multitude of little steps, and that would have been a bit too much for me. Luckily that is not the case.

I'll be following your progression with a lot of interest. I'm all for a sturdy (and not too difficult  :Wink: ) model that can be used for many planets.

Cheers - Akubra

----------


## Azélor

I still don't know exactly where I am heading. It's moving slowly like the oceanic currents and don't know where it's heading.

----------


## Akubra

As long as you keep afloat in those currents, you'll be alright, Azelor.  :Wink: 
Cheers - Akubra

----------

