Tuesday, 20 January 2015

Redesigning the Setting: Drawing the Satellite View Map, 3

Last time we ended with a GIMP drawing with a transparent layer for your plates. I was going to skip right to drawing the outline of the continents until I realized that I was missing a step and that is understanding where the general climate zones will be. Both together are important and here's why:
Subduction Zone - Rocky Mountains

  • On coastlines where you have mountains near the water, those coast lines will tend to be more jagged especially the closer you get to the poles.) That said, even when you have mountains running parallel to a coast line you could still have smooth sections of coast line. This is because where 2 plates collide and form mountains will not always be right at the edge of the water. A subduction zone will often start out a distance at sea and the lighter rock of the continent will stay above it. See the image to the right.
  • In the areas where you have deserts meeting coastal areas, tropical beaches, etc. you will likely have smoother coastlines due to long stretches of sand. This isn't always true of course but it's a good rule of thumb. That means you need to understand, generally where these areas will be on you map. 
The earth has a number of climate zones that correspond roughly to specific latitudes. Whether they are damp or dry will also depend on the atmospheric geography of those areas. See the image to the right. You'll notice correspondences between damp tropical regions and desert regions because of where the winds are carrying moisture and dropping it. Reference the diagram below. You'll see the directions of the winds and the high and low pressure zones. At HIGH pressure zones you have dry air that has cooled falling back down to the surface. Because it has little to no moisture the areas where this air falls are likely to be dry. As the air moves across land and water it will become more humid, carrying more water vapour. It will eventually lose that moisture as rain or fog when it cools and looses its ability to carry that water vapour. It will cool when it gets forced to a higher elevation by a land formation such as a mountain or at a LOW pressure zone or when it meets a cool body of air. This diagram will also help you understand the wind patterns and how maritime peoples on your continent might get around by ship (i.e. where your tradewinds will be.)
The last item you need to be aware of is the heating of the earth due to the Sun, it is the combination of the heating of the atmosphere and spin and tilt of the earth that drives the climate. So, as you draw your coast lines, you'll want to have a general idea of which latitudes your continent span and what the climate is like around those areas. What I did was to add some drawings like these as layers to my image and set the opacity low as I was drawing my coastline so that I had a reference point. We'll talk more about that in the next post.