Original Project
Weathering, Erosion, and Deposition
The surface of the earth is changed as rock material is broken, carried, and dropped in new locations.
Item WE060001: The shape of a valley floor changes when ice breaks rocks as it moves (as in a glacier) and also when water freezes in cracks in the rock of the valley floor.
Which of the following is TRUE about how ice could help to change the shape of a valley floor over many millions of years?
- The shape of the valley floor can only be changed by ice when the ice breaks rocks as it moves (as in a glacier).
- The shape of the valley floor changes when ice breaks rocks as it moves (as in a glacier) and also when water freezes in cracks in the rock of the valley floor.
- Ice can break the rock of the valley floor when it moves as a glacier and when it freezes in cracks, but these processes do not help to change the shape of the valley floor.
- Neither the movement of ice (as in a glacier) nor water freezing in cracks are strong enough to break the rock of the valley floor, so these processes cannot help to change the shape of a valley floor.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 1302 | 2521 | 52% |
| Grades | |||
| 6–8 | 751 | 1526 | 49% |
| 9–12 | 547 | 985 | 56% |
| Gender | |||
| Male | 624 | 1222 | 51% |
| Female | 660 | 1256 | 53% |
| Primary Language | |||
| English | 1164 | 2222 | 52% |
| Other | 110 | 227 | 48% |
- NRC Framework
- Grade 5 ESS2.A Water, ice, wind, living organisms, and gravity break rocks, soils, and sediments into smaller particles and move them around.
- Notes
- See also ESS2.C, Framework p. 184: ...ice expansion contributes to rock erosion...