1. Scraping the desert floor to make geoglyphs was no doubt a lot of work for the Nazca people. What purpose do you think these features served for the people who made them?

2. Regs composed of lag deposits and regs composed of desert pavement look alike on the surface. If you were in a desert and standing on a reg, what evidence would you look for to determine which process formed that particular reg?

3. What would happen to the great Saharan and Arabian ergs if the monsoon were to return to the interior desert, bringing summer rainfall?

4. What do you think would happen to the Aral Sea ecosystems and local economies if water diversions were stopped and the sea was allowed to refill?