Back Home

ACT Question for July 26th

Seashore cliffs often lose rock or sediment to wave erosion. The Figure shows cliff compositions; cliff heights, in meters (m); and the net change in mean high water mark (MHWM), in m, from 1880 to 1970 along a section of shoreline. A net negative change in MHWM indicates a net loss of' rock or sediment and a net positive change indicates a net gain of sediment.

The following table shows the percentage of a year that vertical sections of a cliff are exposed to wave erosion:

Based on the information in the Table, a cliff section with a height of 4.0-4.5 m above the zero baseline would be exposed to wave erosion approximately what percentage of a year?