Frost wedging is a type of mechanical weathering caused by frost and ice. Water expands when it freezes, and repeated cycles of freezing and thawing slowly weaken the structural integrity of porous and cracked rocks. Over time, frost wedging enlarges tiny cracks into huge fissures. The fissures eventually split the rock completely.Know More
Frost wedging is a slow, cyclical process. During the day, liquid water warmed by the sun trickles into microscopic pores, cracks and spaces in rock. When the sun sets and the temperature drops, the water freezes and expands by 9 percent, exerting pressure on the surrounding rock. When the sun rises again, the frost melts and the water flows deeper into the expanded crack, where it freezes after sunset.
The most obvious evidence of frost wedging is the flat, plate-like surface created when the expanded rock joints finally split. Huge rock formations shaped by glaciers often display such sharp, flat faces. Frost wedging occurs only in climates that are cool to cold throughout the year. Canada, Scandinavia, northern Russia and Antarctica are particularly prone to this kind of weathering.
All types of weathering take place over time. However, biological factors that weaken rock serve as catalysts, decreasing the amount of time necessary for drastic change to happen. For example, moss and lichen weaken and destabilize small cracks in the rocks where they grow, making the material more vulnerable to the effects of expanding frost.Learn more about Erosion & Weathering
Silt is made from mineral and rock particles that are smaller than sand. Some particles of silt are so tiny that they are very hard to see with the naked eye. Particles in silt are less than 0.002 inches across, and silt is found in soil and deposited and transported by wind, ice and water.Full Answer >
Poor agricultural practices, deforestation and the overgrazing of livestock are some of the causes of soil nutrient depletion. These activities ultimately lead to soil erosion, waterlogging, salinization and desertification, which is when soil loses 10 percent of its productivity.Full Answer >
Acid rain cannot possibly be stopped fully but can be reduced in several ways including switching fuel sources to natural gas, oil, or renewable energy sources, removing the sulfur from the coal before burning and burning it more efficiently, using fluidized-bed combustion processes to burn the coal, switching to low-sulfur coal and removing the sulfur from the smoke stack after combustion through the installation of pollution control equipment.Full Answer >
The four types of coastal erosion are solution, hydraulic action, abrasion and attrition. Solution erosion occurs when the ocean’s water is acidic. The acidic water causes some of the rocks along the beach to dissolve into the water. Chalk- and limestone-based coastlines are particularly susceptible to this type of erosion.Full Answer >