What is Mass Wasting? | Geography | iKen | iKenEdu | iKenApp

Summary

Mass wasting, or mass movement, refers to the downhill movement of loose material due to gravity, often influenced by water, wind, and glaciers. This process includes both slow (soil creep, rock creep, and solifluction) and rapid (landslides, earth flow, mud flow, and sheet wash) movements. Landslides, the most common rapid movement, can be triggered by earthquakes or heavy rain. Mass wasting shapes diverse landforms like meanders, terraces, and escarpments, impacting landscapes worldwide.

Takeaways

• 🗻 **Mass Wasting Defined**: Mass wasting is the large scale movement of loose material, derived from weathering of bedrock, down a slope due to gravity.
• 💧 **Contributing Factors**: Water, wind, and glaciers contribute to mass wasting, but gravity is the primary driving force.
• 📉 **Influence of Slope**: The steeper the slope, the more rapid the movement, indicating a direct correlation between slope angle and movement speed.
• 🔍 **Types of Movement**: Mass movements are categorized into slow (like creep and solifluction) and rapid (like landslides, earth flow, mud flow, and sheet wash).
• 🌪️ **Creep Movement**: A slow movement involving the gradual downward movement of debris, either in the form of soil creep or rock creep, influenced by seasonal conditions and rock distortions.
• 🏔️ **Rock Creep**: Unlike soil creep, rock creep involves unweathered rock blocks and is less affected by seasonal changes, more by rock resistance.
• 🌊 **Rapid Movements**: Rapid movements are primarily influenced by water, with landslides, earth flow, mud flow, and sheet wash being the main types.
• 📉 **Landslides**: A significant and observable rapid movement where water is not the main factor, involving both rocks and soil with a defined shear plane.
• 🌊 **Earth Flow**: Occurs when waterlogged material moves down a slope, common in areas with rich alluvium soils and on hillsides.
• 🌿 **Vegetation Impact**: Mud flows are more common in areas lacking vegetation and with steep slopes, often triggered by rainfall in arid regions.
• 🌍 **Environmental Impact**: Mass movements affect landforms, creating features like meanders, terraces, scars, ripples, and escarpments, and can be influenced by deforestation.

Q & A

What is mass wasting?

Mass wasting is the large scale movement of loose material derived from the weathering of bedrock down a slope, also known as mass movement.

Why is it called 'mass wasting'?

The term 'mass wasting' is used because the loose material is essentially rock waste, and the movement down the slope due to gravity leads to the waste of rock debris.

What are the contributory factors in mass wasting?

Contributory factors in mass wasting include the presence of water, wind, and glaciers, although gravity is the primary driving force.

How does the steepness of a slope affect mass wasting?

The steeper the slope, the more rapid the movement of mass wasting, as gravity's effect is amplified on steeper inclines.

What are the two main categories of mass movements?

Mass movements can be divided into two main categories: slow movement and rapid movement.

What are the two main types of slow movement in mass wasting?

The two main types of slow movement in mass wasting are creep, which includes soil creep and rock creep, and solifluction, where clay moves as a thick viscous fluid.

How does seasonal climatic condition affect soil creep?

Seasonal climatic conditions play an important role in soil creep, unlike rock creep which is more affected by distortions and bends in rocks offering resistance to gravity.

What are the four major kinds of rapid movements in mass wasting?

The four major kinds of rapid movements in mass wasting are landslides, earth flow, mud flow, and sheet wash.

What is a shear plane and why is it significant in landslides?

A shear plane is a surface which breaks off and on which movement takes place. It is significant in landslides as it characterizes the movement of both rocks and soil.

What triggers landslides and how do they occur?

Landslides are often triggered by earthquakes, heavy rainfall, or wind action. They occur when support in front of a rock or mass of debris is removed, leading to downslope movement.

How does deforestation contribute to sheet wash?

Deforestation contributes to sheet wash by increasing soil erosion, where large sheets or layers of soil are removed by agents of gradation like water, wind, or glaciers.

What landforms are created by mass movements or mass wasting?

Mass movements or mass wasting create varied landforms such as meanders, terraces, scars, ripples, escarpments, and messages.