Erosion! Once a rock is weathered, it usually moves from one place to another. This process is called erosion.
Erosion is caused by the following: a. gravity b. running water c. glaciers d. waves e. wind
Gravity This is the force that moves rocks and other materials downhill. Gravity causes mass movement - when a WHOLE lot of materials move downhill at once. Different types of mass movement include: a. landslides b. mudslides c. slump d. creep
Landslides The most destructive kind of mass movement Occurs when rock and soil slide quickly down a steep slope Common where road builders have cut through hills or mountains.
Mudflows Rapid downhill movement of mixture of water, rock, and soil Often occur after heavy rains in a normally dry area Can be deadly!
Slump mass of rock and soil suddenly slips down a slope in one large mass Creep very slow downhill movement of rock and soil. so slow you barely notice it. may tilt objects at spooky angles (like tombstones, fence posts)
Slump
Creep
Moving water is the major agent of the erosion that has shaped the Earth's surface. There are several ways the water erodes material: a. Gravity and rain b. Rivers c. Groundwater
Gravity and Rain Rain that doesn't soak into the ground, is runoff As runoff travels across the ground, it forms tiny grooves in the soil called rills Rills flow into each other, growing larger and forming gullies Rills and gullies carry soil and rock away from an area. Gullies only flow after it rains.
Through erosion, a river creates: a. valleys b. waterfalls c. flood plains d. meanders e. oxbow lakes
When rain falls and snow melts, some of the water soaks into the ground Causes erosion through chemical weathering Water and carbon dioxide combine to from a weak acid that breaks down limestone Over time, pockets are hollowed out underground and caves form. Karst topography Groundwater
Karst Topography
Waves Water is an extremely strong force As it continually pounds the land, it actually causes the rock and soil to break apart, then be carried away