Mapping an Earthlike planet

[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...

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.

Rautah_Height_V2.png

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.

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

[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

[Akubra]

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

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

Cheers - Akubra