Soil and Glaciers
Size grades of soil are named sand, silt, and clay, which includes colloids. Size grades are defined using the metric system. Use Figure 4. 8 from the textbook to fill in the following chart. Specify the type and size and description of the particle. In some cases, particle size will be less than some value or greater than another value. For instance, gravel is greater than 2. 0 mm. Name Size Description Gravel >2. 0 mm A loose aggregation of small water-worn or pounded stones. Sand 0. 05mm A loose granular substance, resulting from the erosion of siliceous and other rocks. Silt 0. 002mm
Fine sand, clay, or other material carried by running water. Clay 0. 0001mm A stiff, sticky fine-grained. Often forming layers in the soil. Colloids 0. 00001mm A homogeneous, noncrystalline substance consisting of large molecules or ultramicroscopic particles of one substance dispersed through a second substance. Part 2 Soils have been classified according to a system developed by soil scientists and the U. S. Soil Conservation Service. Using this classification system of soil orders, pick two locations on Earth, one in your current area and another area, and describe the order and the conditions that define it.
(See Figure 4. 12 in the textbook. ) 1. Entisols – Soils lacking horizons, usually because their parent material has accumulated only recently. 2. Vertisols – Soils of subtropical and tropical zones with high clay content and high base status. Vertisols develop deep, wide cracks when dry, and the soil blocks formed by cracking move with respect to each other. Part 3 The five important soil-forming factors are indicated in the following table. Describe why these factors are important in the formation of soil. Soil forming factor Importance in soil formation Parent material Is soil. Soil is developed from regolith.
Regolith is of two different kind. Residual and transported. Regolith comes from the underlying rock whethers in its place. Transported develops on sediment that has been transported regolith develops on sediment. Climate Soils with poorly or well-developed horizons causes changes in the soil. Living organisms Micro-organisms like bacteria and fungi break the organic matter down. Animals like worms, mice, moles burrow in soil which help mix components and also provide ways for water and air to pass. Topography The slope helps the ability of water to soak into regolith. Time It takes thousands of years for a mature soil to develop. Part 4
Investigate two ways in which water shortages, erosion, water diversion, floods or contamination of a water resource, or other water processes have affected human history. How did humankind meet the challenges of the impacts? Part 5 In 150 words, how do glaciers form, grow, and shrink throughout time? Cite any references used and provide a References page. ~ Glaciers are formed when snow builds up for several years from snowfall that exceeds snow melt. Over time, as new snow compresses the existing snow, the weight causes the snow underneath to turn to ice. The hardening effect is similar to what happens when you pack a snowball in your hand.
The pressure from additional layers of snow builds for up to thousands of years. Glaciers can grow and shrink as a result of changes in the amount of snowfall or changes in the amount of melting because of warming. Changes in snowfall can result because of changes in the overall annual precipitation, or changes in the timing of the precipitation. Changes in melting can occur as a result of increased average annual air temperatures, and/or changes in the solar radiation. Melting will be affected if the glacier is covered by moraine, dust, or soot particles (increases heating, or an insulator).