Advice on accuracy of world map

Question

My friend and I are working on a map of a globe. The setting of this universe involve various intelligent animal species divided into 5 clades: Archo (Crocodilians), Avians (Birds), Aquatics (Fish), Eutherian (Mammals) and Saurians (Lizards). Each clade is suited to a different environment.

The images below were produced by overlaying different black-and-white images of landmasses. The BW images are produced using a random terrain generator. You can see the image projected on a globe here: https://www.maptoglobe.com/HyOmcSuz8

As a general description world: The world is composed of many islands, archipelagos, gulfs and isthmus. It is divided into three continents. Lets call them Left, Middle and Right. The Left continent has regions of tropical forests, deserts and tundras. The desert is divided into three sections by mountains. There is a long river running through the desert. The Middle is tropical and it is contains many island chains. The Right is also mainly forest but there are section where it touches the North Pole.

This is the flow of sea current. The orange arrows are warm water, blue arrows are cool water, and the green arrows are average temperature. White arrows show the direction of current. The land areas that are spray painted red are warm humid coasts with corals. Blue is stiller water with fishing. Purple is El nino hotspots.

https://i.sstatic.net/h8GnY.jpg

This the tectonic plate map. The arrows show the direction of movement of the plates and the colours indicate a trench (violet) or a mountain (red) https://i.sstatic.net/SLqnO.jpg

Currently the maps appears fine to us for the most part. However we want a second opinion of someone(s) more experienced. The issues that I have right now is the edges seem quite jagged and I'm not sure if that is possible at that scale. The continents also have many cracks and holes in them. Is this possible? And if so, what are the criteria for them to occur? Finally, is the map accurate? Given the ocean currents and tectonic plate positions, is it possible to create these landmasses depicted on the map?

EDIT: Thanks for all the advice. These are the updated maps. Decided to use the Aitoff projection because it gives a better sense of the area. We're still open to any suggestions on the world as well as any advice on the map-making process.

Answer 1

(Note: since it isn't otherwise specified, I'm assuming that the planet is overall fairly Earthlike. Similar axial tilt, seasons, day length, temperature range, etc. If it's not, a lot of this goes out the window.)

Left Continent

Overall, this continent has a strong South America feel, with a bit of a twist. South America has the Andes along its west coast, caused by the Pacific plate subducting under the South American plate. Instead, you have three plates all crashing into one another in the center of this continent. That's going to result in a Himalaya-style plateau instead. Unless you have a giant volcano hiding somewhere, your world's highest mountains are going to be in that range. To the eastern side of that, you have a warm-water coast with an onshore current on the equator, which definitely reminds me of the Amazon-basin. So that deep gray cut into the center of the continent would be an outflowing river, rather than an oceanic inlet. On the western side, you have a cool current in the rain shadow of a giant mountain range, which is going to give you extremely dry deserts like the Atacama in Chile. The north is going to be a hot, dry desert, much like Northern Africa.

In the south, that large sea is likely to give that part of the continent a very Mediterranean feel; the whole area's likely to be something like an inverted Europe. I'll note that you have a "warm" coastline marked at about 60*S latitude, which is about the level of Norway or southernmost Greenland. So "warm" is going to be somewhat relative, unless your world has a much steeper axial tilt than I'm expecting. The "warm" area right above that is about the level of Spain, but it's climate is probably going to be closer to the Pacific Northwest.

Middle Continent

To be honest, geographically speaking, this continent/archipelago is a bit unusual. What I can think of is that the whole continent is relatively flat and very low-lying, so the seas between the islands are quite shallow. Very wet and tropical throughout, much like Southeast Asia. The northern coast isn't going to be "cool", though. 25*N is the same latitude as the Gulf of Mexico. You're going to see hurricanes forming along that coast in the summer and fall, although they're mostly going to swing north away from the continent and into open water. The southeast of that continent will definitely get smacked with hurricanes, though, spinning up in the ocean south of Right. And if the terrain is flat overall like I'm thinking, they're going to go all the way across, regaining power over the extremely warm inner seas.

I must say that I disagree a bit with how you have the plates moving in the ocean to the north. You have three plates coming together, which should be enough to form more than a relatively small island chain. To me, that looks more like a mid-ocean rift, with the two northern plates moving away from one another and islands along the border being highly volcanic. Basically, they're like Iceland, although the climate is going to be more along the lines of New Zealand.

Right Continent

The feel I'm getting from this continent is basically North America with Southeast Asia in place of Mexico. The northern part of this continent is going to be much like Canada or Russia, with boreal forests fading into tundra as you move further north to the pole. The warm spot on the west coast I'd expect to be somewhat like northern France. My initial thought was the US Pacific Northwest, but without a mountain range like the Rockies keeping the moisture on the coast, you won't get the same sort of temperate rainforest. On the other hand, if you reverse the tectonic direction in the ocean to the east, you could put another plate division on the coast and then you would have a coastal mountain range.

The southwest "cool" would probably be much like southern California, actually. The purple southern coast would definitely be tropical, with the large island to the east in roughly the same position as the Philippines. The blue area above it is going to be a lot like Japan if there's any sort of mountainous terrain there.

Tectonically, you don't typically see plates going from ocean to continent to ocean like the northern one does; one coast or the other probably needs a faultline along it. As I mentioned above, my vote's on the west coast. You'll also have a rift valley splitting the continent east-west where the southeast plate is moving away from the northern one, and the southeast is going to see volcanic and earthquake activity where that small plate gets pushed north by the southwest plate sliding past.

Answer 2

It looks really good! I love how much thought was put into the thermal currents, and the direction of plate movement which (I assume) will directly impact the sort of terrain that can be found where these plates meet and contest one another. Looks like there will be lots of mountains. Also, you can absolutely have numerous lakes and large depressed areas in large continents. That causes no problem. The Aral and Caspian Seas and numerous other decent-sized inland lakes and seas exist in Asia, so I don't see why your world's water system wouldn't be similar. Only one thing - it appears you have some warm, humid coastlines at fairly extreme latitudes. If this is a globular planet, would you expect to find those sorts of climates so close to the presumably arctic regions?

Answer 3

My world building project creates a 6000x2800 "image" that is used to map the elements on. Each pixel is a 4x4 km area. The jagged edges of the continents is done at this 4x4 km granularity... your map is fine in this regard. Only you know how much detail you are planning on zooming to for the rest of your design. Depending on how much of your map you will be adding details to like this, you will have a major bit of mapping work to do.

Your ocean current diagram seems off to me. Ocean currents traverse warm zones to cold zones, thus the warm will push north or south and then flow in the reverse once it cools off. The spin of the planet also contributes to this flow, think of how a toilet water spins differently in the northern and southern hemispheres. This means your currents will swirl the same directions in each hemisphere, anchored along your equator. Notice the hot and cold sides of circulation on this diagram of the Earth. Also notice the equator currents flow mostly like the Earth is spinning under the water, thus they flow west to east.

Air currents do similar things. Think of the air layer as loose fitting with the world trying to spin under it, so the features of land and open ocean create turbulence at a global scale. Evaporation, rain etc. all combine to create weather.

Tectonic plates are important if you want to identify volcanic and earthquake zones. Most of the "movement" is so slow it doesn't come into play in a normal campaign or world story. If you are dealing with this kind of timeline, then the movement of these plates might be important for other purposes.

Answer 4

The jagged edges could be explained if your world went trough some extreme glacial eras (with the ice reaching the equator). One thing I notice is that the sea area is small in proportion to the land area. This would imply a land with a lot of mountains because al the plates of emerged land would be bumping and rubbing against each other. So this could explain the rough landscape.

But in this world you would miss the remote place with the mysterious people isolated from the rest of the population.