REVIEW: Lesson Summary

Summary

1916 Flood in Asheville, NC. Photo courtesy of Wikimedia. 

• A sudden release of energy stored in rocks causes an earthquake.
• Liquefaction is caused by the shaking of water-saturated sediments during an earthquake. 
• Liquefaction causes the ground to lose the strength to support structures and roads
• Seismic waves rarely kill anyone. Structures falling on people and fires or tsunamis after the earthquake cause many more fatalities
• City planning can lessen the damage done by earthquakes
• Population density and ground type can affect the number of fatalities
• Tsunami have relatively low wave heights, so they are not noticeable until they move up a shore
• Tsunami have long wavelengths.
• Tsunami warning systems have been placed in most locations where tsunamis are possible. 
• Hurricanes originate over warm tropical oceans
• The damage hurricanes cause is largely due to storm surge, high winds and heavy rains
• Hurricane Katrina was the one of the costliest hurricanes 
• when the amount of water in a drainage exceeds the capacity of the drainage, there is a flood
• Floods are made worse when vegetation is cleared, when the land is already soaked or when hillsides have been logged
• People build dams and levees to protect from flooding
• Floods are a source of nutrients on a floodplain 
• It's hard to define a heat wave or a drought because these phenomena are deviations from normal conditions in a region
• A heat wave is caused by a warm, stationary high pressure cell
• Drought has severe consequences depending on its duration and intensity