Earth Sciences 1022A/B Lecture Notes - Lecture 14: Solifluction, Porosity, Permafrost

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1022A/B
• Professor: Stephen R Hicock

Document Summary

Earth sciences 1022a lecture 14 mass wasting. Gravity: is the most important, but water is also critical, gravity is always pulling rock, regolith, and soil down slopes. Its more effective if: when water completely fills pores it reduces cohesion and allows grains to slide over each other, it adds weight to soil. Over steepened slopes: due to undercutting by waves, streams, and human excavation, resulting in loss of support for materials higher up the slope. Vegetation: anchors soil and regolith with plant roots, removing plants make the slope unstable and susceptible to failure. Earthquakes: can dislodge rock and unconsolidated material, resulting in landslides. Based on types of materials, types of motions (freefall, sliding and flowing), and how fast they move. Earth flow: slower movement of soil and regolith under gravity, caused by repeated freezing and thawing, wetting and drying, or water saturation following heavy rain or snowmelt, results in tilted trees, fences and utility poles.