Section 1.5: Exercises

1. Using Google Earth©, find another major river delta (e.g. the deltas of the Amazon, Nile, Congo, Indus, Mekong, or Yellow Rivers, etc.). What geographic features does this other river delta have in common with the Mississippi? Can you find any significant differences?

2. Looking at your selected alternate river delta, zoom in and examine the human-made features of the landscape. Do you see evidence for the presence of levees or other such hydrological features? Where are the cities and towns located relative to the various geographic features of the delta? Why do you think this might be?

3. Do you see places where you think that sediment might be accumulating? Do you see places that seem like they might be experiencing coastal erosion? Can you make any guesses as to why particular locations might be experiencing either sedimentation or erosion?

4. Go outside and collect a cup-full of dirt. If you have a microscope (or even a magnifying glass), look at your dirt under magnification. You should be able to see the particles of your sediment. How big are they? What do they look like?

5. Add your dirt sample to about an equal amount of water in a sealable container (i.e. a jar or water bottle), leaving some air at the top of the container. Shake your container thoroughly and watch what happens to the suspended sediment. How long does it take for the sediment to start settling at the bottom of the container? What kind of sediment settles first? What kind of sediment stays suspended longest? What can you say about the relationship between how long sediment stays suspended and the grain size of that sediment?