front 1 Define mass wasting. | back 1 The downslope movement of sediment and rock under the direct influence of gravity. |
front 2 A __________ is formed when vertical incision by a stream is the primary process, with relatively minimal mass wasting. | back 2 slot canyon |
front 3 Which of the following correctly states the role of rivers and mass wasting in the formation of the Grand Canyon? | back 3 The Colorado River erodes downward, then mass-wasting processes move material from high to low areas, then the Colorado River transports material downstream. |
front 4 Over time, mass wasting causes __________. | back 4 canyons to widen |
front 5 What rock type is the easiest for a river to cut through? | back 5 shale |
front 6 The Gros Ventre slide is evident today by __________. | back 6 a scar, runout area, and landslide debris filling the valley |
front 7 Which of the following is a reason the Gros Ventre rockslide took place? | back 7 Because the river eroded material at the valley base, there was no support of the material upslope. |
front 8 A __________ acted as a sliding surface across which material moved downhill during the Gros Ventre Slide. | back 8 clay layer |
front 9 Heavy rainfall caused the clay to lubricate and the sandstone to become __________. | back 9 saturated and heavy |
front 10 Which of the following statements is true regarding the aftermath of the Gros Ventre rockslide? | back 10 The rockslide debris dammed up the river and formed a lake. |
front 11 Creep is __________. | back 11 mass wasting by the gradual downhill movement of sediment, influenced by freeze-thaw or wet-dry cycles |
front 12 Describe how a soil particle moves downhill during the freeze-thaw process. | back 12 During the freeze, a soil particle moves at a right angle away from the surface, and thawing causes the particle to fall back to a slightly lower level. |
front 13 Why would trees be J-shaped? | back 13 The trunks become tilted in the downhill direction due to creep, but continue to grow toward the sun. |
front 14 Which of the following is associated with creep? | back 14 slow and subtle movement of material |
front 15 A __________ is a common result of creep. | back 15 broken retaining wall |
front 16 Permafrost is __________. | back 16 permanently frozen ground of tundra and subarctic climates that has remained 0°C for two years or more |
front 17 __________ is an example of mass wasting commonly seen in the active layer above permafrost. | back 17 Solifluction |
front 18 What is name of the near-surface layer that thaws in the summer? | back 18 the active layer |
front 19 If permafrost is melted, which of the following is a consequence? | back 19 The ground subsides because the volume of water is less than that of ice. |
front 20 What is used to keep the Trans-Alaska pipeline from melting permafrost? | back 20 stilts |
front 21 Mass wasting is possible only with the aid of a transportation agent such as water, wind, or ice. | back 21 False |
front 22 What non-geologic term is commonly used to describe a sudden event in which large volumes of material move down steep slopes? | back 22 Landslide |
front 23 What is the angle of repose? | back 23 The steepest angle at which a material remains at rest |
front 24 The 2005 mass-wasting event in La Conchita, CA, can be classified as a ______. | back 24 debris flow |