Passage II

Mass movement is the movement of soil or rock down a slope. Two types of mass movement are soil creep and block glide (see Figure 1).

Scientists studied soil creep at 3 sites (Sites 1-3) and block glide at 3 other sites (Sites 4-6) in a particular region. Beginning on March 1, 1995, and every 6 months thereafter until September 1, 1998, the scientists measured the cumulative distance that material at the surface had moved since September 1, 1994. Figures 2 and 3 show the results for Sites 1-3 and for Sites 4-6, respectively. Each figure shows the amount of precipitation that fell at each of the 3 sites over each 6 month period.

Figures 2 and 3 adapted from D. N. Swanston, R. R, Ziemer, and R. J. Janda, "Rate and Mechanics of Progressive Hillslope Failure in the Redwood Creek Basin, Northwestern California." U,S. Geological Survey Professional Paper 1454-E, 1995.

12. According to Figures 2 and 3, over the study period, was the cumulative distance that material moved due to soil creep less than or greater than the cumulative distance that material moved due to block glide?

Answer and Explanation

Your Answer is

Correct Answer is G

Explanation

Comparing the ordinates on the left side of figure 2 and figure 3, figure 2 studies soil creep, and its ordinate corresponds to a maximum of 1.4 m; while figure 3 studies block glide, and its ordinate corresponds to a maximum of 64 m left and right