Realistic Islands - form & arrangement

[Sonnenfalke]

Hellow fellows,

I'v used the search function but haven't found anything helpful, so I'm trying it here:

1st: My problem is how to create realistic looking islands? On earth we have a lot of islands with different looks but if I'm drawing islands by myself they are looking unrealistic - like random coastlines/mountains with no sense. So does an island every time has an high point (mountain, vulcan etc) with lower coastline around or are flat islands with palm trees or so more realistic? What about water on larger islands - where does it comes and where did it go? Same rules like in the thread of the River Police?

2nd: the arrangement of islands

Should an island look more like a broken peace from a bigger continent? And how far should it be away from the continent itselfs? What about groups of islands? Are they more "one broken island with water between" or have they more their own form/coastline mountains a.s.o.?

I think its much complicated to create realistic looking islands in combination with larger continents. So if there are any rules for creating an island that doesn't look like a green or yellow spot in the water it would be really helpful.


best regards
o/

[Ghostman]

There are different ways that islands can form, and this will influence how they end up looking like.

* Where an oceanic plate collides with a continental plate, the former will "sink" under the latter. This kind of plate boundary might create a chain of volcanic islands the run somewhat parallel to the continental coast. For example, the Japanese islands and the Philippines.

* Where two plates are moving away from each other, the boundary between them is constantly "opening" the seafloor, thus causing hot magma to rise from underneath. Sometime the magma can reach the surface, creating volcanic islands. Iceland is a particularly large island created in this manner.

* Volcanic hotspots are places where magma frequently penetrates and erupts through a plate. If the spot happens to be over a sea, it may create volcanic islands. Because the plate is constantly moving but the hotspot remains in place, the islands will tend to form as a chain along the direction of the plate's movement. Hawaii is an example of this type of islands.

[Meridius]

Ghostman describes mostly volcanic islands. Which are more of an exception. For a lot of the worlds islands, it helps if you stop thinking about them as if they where islands, and start thinking like they where mountain-peaks, which is exactly what they are.

The relief of our planet doesn't 'end' at the sea. The sea is just an alternate filling, opposed to air. Sometimes there are more or less 'lone' mountain peaks on land, which means those also exist underseas. Sometimes they are so high, not all of it is covered under water. That is an island.

There are in fact other ways for islands to come into being. If I recall correctly, the Canary Islands are in fact located on top of a kilometres thick stack of shells of dead sea-animals.

Along the coast, islands often come into being from sedentary processes. Rivers corrode mountains, this corrosion floats downstream, and at the rivermouth into the sea, this sediment gets dumped, if enough is dumped, islands form. Sediment-islands usually get shaped by water currents.

I hope this is useful