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Erosion and WeatheringNatural hazards Made By: Haley Cioni and Madison Keegan Weathering • Weathering is the breaking down of rock, soils and minerals as well as artificial materials through contact with the Earth’s atmosphere, biota and waters. • Two important classifications of weathering processes exist – physical and chemistry weathering; each sometimes involves a biological component. • The materials left over after the rock breaks down combined with organic material creates soil. Erosion • Erosion is the process by which soil and rock are removed from the Earth’s surface by natural processes such as wind or water flow, then transported and deposited in other locations. • Water and wind erosion are now the two primary causes of land degradation ;combined they are responsible for 84% of degraded acreage. Different Types of Weathering Different Kinds of Weathering and Erosion Causes of Weathering and Erosion • Atmospheric erosion-the suns heat causes surface rocks to expand and fracture, and moisture can evaporate. • Biological erosion-many plants secrete acids in their roots. Root structures also enlarge cracks seeking water. Animals crush surface rocks and deposit organic materials that interact with minerals. Factors Controlling the Rate of Erosion • Precipitation and wind speed • Soil structure and composition • Vegetative cover • Topography Differences between weathering and erosion • • • Weathering involves two processes that often work in concert to decompose rocks. Both processes occur in place. No movement is involved in weathering. The two types of weathering are called chemical, and mechanical weathering As soon as a rock particle moves we call it erosion or mass wasting. Mass wasting is simply movement down slope due to gravity. So the difference is that weathering involves staying in place and erosion involves movement. Soil Erosion • Soil erosion by water, wind, and tillage affects both agriculture and the natural environment. • Soil loss, and its associated impacts, is one of the most important of today's environmental problems. Study of historic Hopi Buttes Area • Hopi Buttes volcanic field is a monogenic volcanic field located on the Colorado plateau mostly on the Navajo Reservation around the town of Dilkon. • Most of the volcanic activity occurred between 8.5 and 6 million years ago with the most recent dated 4.2 million years ago. Erosion in the Southwest • Erosion is carving into Southwest Washington beaches. Erosion rates at Cape Shoal water have averaged over 100 feet per year for a century. • In recent decades, new erosion hot spots have developed. Coastal Erosion Prevention • Seawalls, which run parallel to the coast are one of the most common responses two coastal erosion. They help stabilize the beach. • Groynes- are structures that prevent erosion by limiting water flow • Vegetation- planting vegetation such as trees defends the coast line. • Offshore breakwaters- are submerged structures that parallel the shore. Wind Erosion Prevention • Wind erosion happens when the soil is left unprotected from the strong winds. The loss of topsoil lowers the quality of the soil. • This makes it more expensive and harder to grow food crops. • The blowing soil can also plug ditches, make driving more difficult, plug ventilation, equipment and so on. Beach Erosion Prevention • Beach erosion is the movement of beach materials by wave action, currents and tides, or wind. • Many ways to prevent beach erosion are available. Natural dunes and vegetation are slow forming but more durable than unnatural dunes and transplanted vegetation. Man made structures include seawalls, sandbags, and sand fences. Geological hazard: landslide • Landslides constitute a major geological hazard because they are widespread, occur in all 50 states and U.S territories, and cause $1-2 billion in damage and more than 25 faculties on average each year. • Landslides commonly occur in connection with natural disasters like, earthquakes, volcanoes, wildfires, and floods. Federal Emergency Management Agency- Landslides and Mudslides • The Federal Emergency Management Agency (FEMA) is a agency of the United States department of homeland security, initially created by Presidential Reorganization Plan No.3 of 1978 and implemented by two executive orders on April 1, 1979. • To prevent mudslides and landslides they look for dues to know when they will occur. Then they will try to prevent them as best as they can. Solution!!! • Some solutions for erosion are seawalls, sandbags, and sand fences. Also some more are gyrones, vegetation, and offshore breakwaters. • This is a way to prevent the worse of weathering and erosion. In the future I believe they will come up with more solutions to prevent these natural hazards. Thanks for watching!!! Reference Page: Part 1 • • • • • • • • http://educatoral.com/weathering_erosion_webques.html http://en.wikipedia.org/wiki/Weathering http://en.wikipedia.org/wiki/Erosion http://facstaff.gpc.edu/~pgore/geology/geo101/weather.htm http://science.nationalgeographic.com/science/photos/weathering-erosiongallery.html#baffin-island_832_600x450.jpg http://wiki.answers.com/Q/What_causes_weathering_and_erosion http://en.wikipedia.org/wiki/Erosion http://geomaps.wr.usgs.gov/parks/misc/gweaero.html Reference Page 2 • • • • • • • • • http://soilerosion.net/ http://en.wikipedia.org/wiki/Hopi_Buttes_volcanic_field http://www.ecy.wa.gov/programs/sea/coast/erosion/study.html http://www.advancedcoastaltechnology.com/ http://www.environment.ualberta.ca/SoilPosters/wind.cfm http://wiki.answers.com/Q/What_causes_beach_erosion http://landslides.usgs.gov/ http://en.wikipedia.org/wiki/Federal_Emergency_Management_Agency http://www.fws.gov/fire/ifcc/esr/Media/FEMA%20landslides%20are%20you %20ready.pdf