Earth 33

Previous ………. Next Topic >

Return to Index

Erosion, Weather & Climate

Weather plays a large part in creating the valleys and mountains we enjoy today. Snow, rain, and wind are important factors in forces of erosion. These forces create deeper canyons, new creeks, wider rivers, and filled-in lakes. Erosion plays a part in determining types of vegetation and animals that with thrive in a location. Climate has an impact on erosion also – except that climate impacts are over long periods of time.

NOTE: There have been at least five major ice ages in the Earth’s history. During such periods of large-scale glaciations (lasting several million years, each), Earth’s surface has been drastically reshaped – even the features of entire continents.

Aside from erosion over long periods of time from climate – there are four types of erosion that are directly observable.

  • Attrition is when small rocks hit big rocks and break them apart. The rocks tumble downstream and strike other rocks.
  • Hydraulic action is erosion from the force of water against a rock surface. This is a form of mechanical weathering similar to attrition. The difference is that attrition is when rocks hit other rocks. Hydraulic action is water hitting against the rocks.
  • Solution erosion could be called chemical erosion. Water with various salinity can break down – even dissolve – some rocks.
  • Abrasion can be by wind or water. Abrasion is when rock or soil is worn away from scraping it. Wind or water carries away small particles of rock, sand or dirt.



Day 1 – Introduction
Day 2 – Virtual Textbook


1:29 River erosion threatens Oklahoma homes

2:07 Types of erosion (coast & river)

9:31 River Erosion, Transport and Deposition

Compare Contrast and Debate

Ideas for this pro/con debate are drawn from BBC. (see full article).

Background: Coastal areas with beaches erode, weather, and change. Sometimes, those changes are abrupt.

Coastal areas with beaches erode, weather, and change. Sometimes, those changes are abrupt. Imagine the force of hurricane winds and monstrous waves crashing on a shoreline. In other instances, changes where land meets sea are slow. But, even when slow – changes do take place.

Certainly many coastal areas are used for tourism and fishing. Homes, condominiums, and other dwellings are frequently built along a coast. Builders, home owners, industrial organizations, trade and transport companies each must consider the benefits and risk being near a coastline. Several coastal management methods are used to control or lessen the natural change in a coastal area. Words sometimes used to describe the categories are “hard” and “soft.”

  1. Hard engineering options may very well be difficult – but, the word hard is not meant to convey “difficult.” Rather, hard engineering solutions make use of strong, massive, and substantial materials to “block” erosion from water, wind, and waves.
  2. Soft engineering solutions might be described as working with nature. These efforts attempt to steer erosion into a particular direction and make the changes predictable and more controlled.

Examples of hard engineering solutions for coastal areas are sea walls and gabions. Examples of soft engineering solutions are beach nourishment and managed retreat.

  • Position A: Coastlines should be left alone. No hard barriers or soft engineering methods should be used to alter natural processes.
  • Position B: Combinations of hard and soft engineering are appropriate to lessen the erosion and weathering of coastlines.

Instructor Resources

Standard Daily Material
  • Day 1 – Standard material – introduction day
  • Day 2 – Standard material – reading day
  • Day 3 – Standard material – make a presentation
  • Day 4 – Standard material – give a presentation
  • Extra! – Enrichment and remediation options
Other Topic Specific Resources

Special Notes and Notices

  • Science & Engineering Practice: Develop and use models.
  • Cross-Cutting Concept: Energy and Matter: Flows, cycles, and conservation.

About us ……… Terms of use