Chapter 1.4, Weathering, & Erosion

Weathering Weathering is the process of breaking surface rock into boulders, gravel, sand, and soil. Weathering can be caused by water, frost, chemicals, and plants.

Weathering Water seeps into crack of rocks and then freezes. When water freezes it expands and can split the rock. Chemicals can eat away the surface of stones and rocks. Tiny seeds can fall into cracks in stones and rocks. As the roots grow and spread, they can break apart rocks.

Weathering

A close-up view of one of the boulders, showing its weathering pattern This is a wide view of the boulder field in Ringing Rocks park. It almost appears as if it is a dry river bed, but it's not.

Erosion Erosion is the process of wearing away or moving weathered material. Water, wind, and ice are the greatest factors that erode, or wear away surface material. Rain and moving water can erode even the hardest of stone over time.

Water Erosion Rain fall causes streams and rivers flow faster. The faster a river flows, the more soil and sand it picks up and moves. The particles in the river water make the water similar to a giant scrub brush that grinds away at the riverbanks and any other surface in its path.

Water Erosion

Wind Erosion Wind Erosion is caused by wind lifting soils and sand. When soil is lifted by erosion, the area it came from loses nutrient soil. However, the area that receives the soil often benefits from the added nutrients to the land. When sand is eroded, the sand being carried by the wind acts as sandpaper grinding away at the things it comes into contact with.

Wind Erosion

Ice Erosion Glaciers are giant, slow moving sheets of ice. They form in mountains Glaciers act as sandpaper as they pick up and carry rocks down the mountainside, grinding smooth everything beneath.

Ice Erosion

Elevation Height above sea level

Plains Plains are low-lying stretches of flat or gently rolling land

Plains Area of level land, usually at a low elevation, and often covered with grasses.

Plateaus An area of flat or rolling land at a high elevation

Isthmus A narrow stretch of land connecting two larger land areas.

Peninsula Body of land surrounded by water on three sides

Island Body of land surrounded by water on all sides

Continental Shelf

The plateau off each coast of a continent that lies under the ocean and stretches for several miles. At the edge of the shelf, steep cliffs drop down to the ocean floor.

Continental Shelf

Map of the Continental Shelf of the U.S.

Trenches Deep valleys that line the ocean floor

Trenches

Mariana Trench

Mount Everest

Strait Narrow stretch of water joining two larger bodies of water.

Channel Wide strait or waterway between two landmasses that lie close to each other

Delta Flat, low-lying land built up from soil carried downstream by a river and deposited at its mouth.