What are the two major forces that shape and reshape earth? Describe how each one works.
plz plz plz help me there are no answer choices hope u can still help
I might suggest you read your text materials. You are not asked questions not covered in class reading assignments.
Failing that, try reading this:
http://igs-galluppiw.wikispaces.com/How+wind,+water,+gravity+and+ice+shape+and+reshape+Earth%27s+land+surface
Of course! I'm here to help. The two major forces that shape and reshape the Earth are tectonic forces and erosional forces. Let me explain each of them in more detail:
1. Tectonic forces: These forces are associated with the movement of Earth's tectonic plates. The Earth's crust is divided into several large plates that float on the semi-fluid layer below. There are three types of plate boundaries: convergent, divergent, and transform.
- Convergent boundaries occur when two plates collide. Depending on the type of plates involved, one plate may be forced beneath the other, creating a subduction zone. This process leads to the formation of mountain ranges, such as the Himalayas.
- Divergent boundaries occur when two plates move away from each other. This movement produces new crust material as magma rises to fill the gap. It leads to the formation of underwater mountain ranges (mid-oceanic ridges) and rift valleys on land.
- Transform boundaries occur when two plates slide past each other horizontally. The movement along these boundaries can cause earthquakes. The San Andreas Fault in California is an example of a transform boundary.
These tectonic processes continuously reshape the Earth's surface through the creation of new landmasses, the movement of continents, and the formation of geological features like mountains, valleys, and trenches.
2. Erosional forces: These forces work to wear down the Earth's surface through the processes of weathering and erosion. Weathering refers to the breakdown of rocks into smaller pieces through mechanical, chemical, or biological processes. Erosion, on the other hand, involves the transport of these weathered materials by wind, water, glaciers, or gravity.
- Wind erosion occurs when particles are picked up and carried away by wind, often resulting in the formation of sand dunes or the gradual removal of surface materials.
- Water erosion is caused by the movement of water over the land. It can occur through various processes like sheet erosion (the removal of a thin layer of topsoil), rill erosion (the formation of small channels), and gully erosion (the formation of larger, deeper channels).
- Glacial erosion happens when glaciers move, carrying rocks and sediments along their path. This leads to the formation of U-shaped valleys, fjords, and other glacial landforms.
- Gravity erosion, also known as mass wasting, refers to the downhill movement of rocks and soil due to gravity. Landslides, rockfalls, and mudslides are examples of this type of erosion.
These erosional forces shape the Earth's surface by carving out valleys, canyons, coastlines, and other landforms, as well as by depositing sediments in new locations.
So, the interplay between tectonic and erosional forces continuously shapes and reshapes the Earth's landforms and topography over long periods of time.