Author Question: Which of the following statements regarding sea-level is false? A) Sea level is a convenient ... (Read 17 times)

dejastew · **on:** Jul 16, 2018

Which of the following statements regarding sea-level is false?

A) Sea level is a convenient reference position because it is constant.
B) The edges of continents submerged today were dry land at times in the past.
C) Marine sedimentary rocks in present day continental interiors indicate times when continents were submerged.
D) There is a connection between average lithosphere age and sea level.

Question 2

How do human activities affect soils?

What will be an ideal response?

parshano · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

Answer: A

Answer to Question 2

Answer: Plowing and cultivation disturb soil horizons. Agricultural activities may also reshape the land surface, which increases water runoff and decreases infiltration into the soil. Bare areas, rows of sown crops, and compacted land surfaces leave significant parts of the field exposed to water runoff and soil erosion. The loss of vegetation, especially during drought, promotes soil erosion by wind. Dry conditions and the lack of vegetation decrease soil moisture and enhance the ability of wind to pick up and move soil particles. Terracing steep slopes and planting parallel to contours diminishes water runoff. Planting continuous covers of vegetation and trees serves as a windbreak and helps retain soil moisture. Practicing no-till methods also decreases erosion by inhibiting water runoff and restores nutrients to the soil.