MT 7: California Geology LT 1: Natural Hazards
Why are we studying CA Geology? We live in California and it is a state standard. Unique geological features and history. Location: West coast of USA, which is on North American continent.
What is CA’s Geology? Where the North American plate & Pacific plate meet Major plate movement and activity. Formed as a result of tectonic plate movement Weathering has also played a role: wind, water, ice, and erosion on surface of Earth formed unique landscape.
What is the unique landscape of California? Sierra Nevada Mountain Range: Very tall and large mountains located on the East side of the state Large Eastern deserts. East side of the mountains and in Southeast California
What is the unique landscape of California? Pacific Ocean: Border of the West side of state Northern California: cooler & receives more precipitation (rain, snow, hail, sleet). Southern California: warmer and receives less precipitation.
What is the unique landscape of California?
How does the landscape cause Natural Hazards? Think, Write, Pair, Share
The processes of the Earth in this region produce Natural Hazards In other words, the movement of the Earth makes parts of California likely to experience hazards humans can’t control!
What is a Natural Hazard? An event that results from Earth processes Can cause damage & endanger human life
What are CA’s Natural Hazards? Storms Earthquakes Volcanoes
What is a Storm? Excess precipitation Winter storms bring Rain, snow, hail, sleet Winter storms bring Rain to lower elevations Snow to the mountains.
What natural hazards are produced by a Storm? MUDFLOWS- A mass of very wet soil or rock that flows quickly downhill Occurrence: Southern California – during & after severe rainfall Northern California – rapid melting of snow causes hazard FLOODING- What is it: Excessive (too much) rainfall & melting snow Northern California River channels filled in short period of time & overflow Mountains & Southern California: Flashfloods: floodwaters rise rapidly & move quickly Agricultural Areas: Can cause dams and levees to fail.
What is an Earthquake? Earthquakes are produced when pressure is released at a plate boundary
What natural hazards are produced by an Earthquake? TSNUNAMIS – A wave formed when the ocean floor shifts suddenly during an earthquake. Can grow to enormous size, gain speed, and act like a powerful wall of water Risk near the California West Coast SIESMIC SHAKING – Measure of ground movement during an earthquake. Buildings, freeways and structures can collapse Risk along fault lines
What natural hazards are produced by an Earthquake? LIQUEFACTION – water-soaked soil turns to a thick, soupy liquid Buildings and other structures quickly collapse in the soft mud. landslides – When loose rock & soil on slopes move Occurrence in areas with: Steep slopes (think mountains) Weak soils Periods of drought Recent forest fires
What is a Volcano? Produced by the subduction of a plate beneath another Location (primarily) Cascade Ranges – Northern Ca Volcanic Fields Area that is covered by volcanic rock Long Valley Caldera – East side of Sierra Nevada Mtns
What natural hazards are produced by a Volcano? Volcanic Ash– Dust produced from burning rock of the volcano. Harmful to plants, animals & human respiratory system Can block incoming solar radiation that is needed to survive Lava Flows– Lava that breaks through surface of volcano & moves down the sides of it Can destroy whole villages & create new land masses. Volcanic Gases-Carbon Dioxide Gas Can be deadly to plants, animals, and people in high concentrations
LT 1 Notes Summary On a separate sheet of paper, answer the following questions in complete sentences: What 3 Natural Hazards commonly take place in California? What are the 4 main earthquake hazards in Ca? What are the 3 volcanic hazards in California? What are two hazards that result from storms in California?