Mass Movement Practice Quiz

Heavy rains help cause mass movement because they cause the soil to become wet and heavy. When the soil becomes saturated with water, it loses its stability and cohesion, making it more prone to erosion and movement. The added weight of the water increases the gravitational pull on the soil, making it easier for it to slide or flow downhill. This can lead to landslides, mudslides, and other types of mass movement.

A rock fall occurs when rocks detach from a steep slope and tumble down due to the force of gravity. This can happen due to various factors such as weathering, erosion, or seismic activity. Unlike other options, such as mudflow, creep, or slump, a rock fall specifically involves the movement of rocks.

Deforestation refers to the removal of trees. This process involves the clearing or cutting down of forests, either for commercial purposes like logging or for creating space for agriculture, urbanization, or infrastructure development. Deforestation has significant environmental impacts, including habitat destruction, loss of biodiversity, soil erosion, and contribution to climate change through the release of carbon dioxide.

Gravity is the force that causes all mass movement. It is the force that pulls objects towards each other. In the context of mass movement, gravity plays a crucial role in pulling loose materials, such as rocks, soil, or debris, downslope. This can result in various types of mass movement, including landslides, rockfalls, or mudflows. While factors like rain, snow, and deforestation can contribute to the instability of slopes and increase the likelihood of mass movement, gravity is the underlying force that ultimately causes the movement to occur.

Mass movement refers to the process where gravity causes the movement of material downhill. This can occur due to various factors such as the saturation of the soil with water, earthquakes, or human activities like construction. When the force of gravity exceeds the strength of the material or the friction holding it in place, the material starts to move downhill. This can result in different types of mass movements like landslides, rockfalls, or mudflows, depending on the characteristics of the material and the slope.

Earthquakes can cause mass movement because they generate strong vibrations and shaking of the ground, which can dislodge and destabilize rocks, soil, and other materials. This can lead to landslides, rockfalls, and avalanches, causing large-scale movement of debris and mass wasting. The intense shaking during an earthquake can also liquefy loose or saturated soil, further contributing to mass movement. Therefore, earthquakes have the potential to trigger significant changes in the landscape and pose a threat to human lives and infrastructure.

Creep is the correct answer because it is a type of mass movement that occurs very slowly over time. It involves the gradual downslope movement of soil and sediments, often due to the expansion and contraction of materials caused by freezing and thawing or wetting and drying. Unlike other types of mass movements like mudflows or rock falls, creep is characterized by its slow and continuous nature, making it the slowest type of mass movement.

After a volcanic eruption, if ice on the volcano melts due to the intense heat, it can lead to the formation of a lahar. A lahar is a type of mass movement that occurs when volcanic material mixes with water, creating a fast-flowing mixture of mud, debris, and water. This mixture can travel down the slopes of the volcano, causing significant damage to the surrounding areas. Therefore, the correct answer in this case is lahar.

Building houses on hills in landslide danger zones is not a good idea because the added weight of the houses can cause landslides. The weight of the structures puts additional pressure on the already unstable ground, increasing the risk of a landslide occurring. This can be particularly dangerous in areas prone to landslides, as it can lead to property damage, loss of life, and displacement of residents. Therefore, it is important to avoid constructing houses in such areas to minimize the risk of landslides.

Telephone polls being tilted on a hill are an example of creep, a type of mass movement. Creep refers to the slow, gradual movement of soil or rock downhill, caused by the force of gravity. In this case, the tilt of the telephone polls suggests that the ground beneath them is slowly shifting and causing them to lean. Unlike other types of mass movement, such as mudflows or rock falls, creep occurs over a long period of time and is often not easily noticeable.

A fast-moving mix of water, soil, and rocks would be a mudflow. This is because mudflows are a type of mass wasting or landslide event where a mixture of water and loose sediment flows rapidly down a slope. Unlike other types of landslides, mudflows have a high water content, which makes them highly fluid and capable of traveling long distances. They often occur after heavy rainfall or in areas with saturated soil, causing the loose material to become unstable and flow downhill.

Planting trees on a muddy slope is a good idea to prevent mudflows and landslides because the tree roots soak up water, reducing the amount of water in the soil. This helps to stabilize the soil and prevent it from becoming too saturated and prone to sliding. Additionally, the trees act as anchors, keeping the soil in place with their roots and preventing erosion. This combination of reducing water content and stabilizing the soil makes planting trees on a muddy slope an effective way to prevent mudflows and landslides.

A slump refers to the sudden downward movement of a mass of material along a curved slope. In this scenario, large chunks of land are falling down the slope simultaneously, indicating a slump. This type of movement usually occurs in cohesive materials, such as clay or silt, and is often triggered by factors like heavy rainfall, erosion, or human activities. The abrupt and simultaneous nature of the land movement distinguishes it from other options like creep (slow continuous movement), lahar (mudflow caused by volcanic activity), or rock fall (falling of individual rocks).

The angle of repose refers to the steepest slope at which material no longer moves downhill. It is the point at which the force of gravity pulling the material downhill is equal to the frictional force resisting its movement. Once the material reaches this angle, it will remain in place rather than continuing to slide or flow downhill.