What you will learn in Geomorphology, Weathering and Landforms

1. 1. Three words that are not synonyms

   Weathering breaks rock where it stands, erosion carries it away, mass wasting lets gravity do the carrying. The difference between the first two is not about how the rock broke — it is about whether it went anywhere.

2. 2. Climate decides the mechanism

   The rock brings its chemistry and the climate decides what can happen to it. Granite in a rainforest ends up as clay; the same granite in a desert ends up as angular blocks that are still granite.

3. 3. The thermostat

   Weathering silicate rock takes carbon dioxide out of the air, and it does it faster when the world is warm. That is a thermostat, it has held the surface liquid for four billion years, and it takes a million years to move.

4. 4. Rivers

   A concave long profile falls out of one equation, a knickpoint climbs upstream after the sea falls, and a meander crosses its floodplain four thousand times faster than the bed drops. That last number is the chapter.

5. 5. Ice, wind, water, rock

   Five processes, five sets of landforms, and one comparison that is worth more than the rest of the list: the same river, in a trough the ice cut and in a gorge it cut itself, thirteen kilometres apart.

6. 6. Reading the ground

   A contour map is a shape written down as a set of closed curves. Read one, commit to what it says, and then look at the ground — with the vertical exaggeration on the label and settable back to one.