ASMO Science Olympiad 2017 — Level 3 (Years 7, 8 & 9) Question 19

Question 19

“Fresh water has a density of 1.0 while salt water has a density of 1.025. Thus salt water is slightly heavier than fresh water. This difference in density causes the pressure under a saltwater column to be greater than the pressure under a column of the same height of fresh water.”

Suppose we dig a well at the top of the fresh water aquifer and pump the water out of it. What is the correct possibility out of given options?

1. Pumping out the fresh water would cause the reduction in pressure. To equalize this pressure salt water would be drawn to the top replacing the fresh water.
2. The reduction in pressure due to pumping of fresh water would be compensated by the other nearby fresh water aquifers.
3. The reduction in pressure would intensify the effect of drawing salt water. First we would draw all the fresh water and then after sometime we would get salt water from the well.
4. To equalise the pressure below ground level, air would be drawn in causing the formation of cracks in the grounds.