Scale Affects Change Practice Test

A class compares two representations of the same glacier at different temporal scales:

• Short-term scale: weekly measurements for 2 months in spring. • Long-term scale: one measurement each year for 30 years.

During the 2 months, the glacier’s front advances slightly during a few colder weeks and retreats during warmer weeks. Over 30 years, the glacier front retreats steadily overall.

Which statement is supported by the evidence at one time scale but not the other?

A coastline is studied using two time scales:

• Representation 1 (short-term): Daily beach photos over 2 weeks show the shoreline moving landward after a storm and then moving seaward again a few days later. • Representation 2 (long-term): A map comparing shoreline position from 1980 to 2020 shows the average shoreline has moved landward over decades.

Which statement is supported by the long-term representation but not necessarily by the short-term representation?