WARM-UP (TURN IN ON HALF SHEET)

• What are five factors that affect soil erosion (from your notes)? Explain how each affects the soil.

GEOHAZARDS

GEOHAZARD

• A geohazard is a geologic event that has the potential to both destroy property and cause a loss of life• Landslide

• Earthquake

• Tsunami

• Sinkhole

• Flooding

• A landslide is where debris separates from bedrock and the material slides rapidly down slope• Caused by:

• Over steepened slope

• Removal of vegetation

• Earthquakes

LANDSLIDES

LANDSLIDES

• Ways to avoid landslide damage• Don’t build homes on areas of weak soil

• Replant trees

• Slopes can be sprayed with concrete to reduce rock slipage

• Earthquakes occur when tectonic plates slide past each other, slip and release seismic waves

• Ways to mitigate earthquake damage:• Secure bookshelves in home

• Secure gas/water heater

EARTHQUAKES

VOLCANOES

• Volcanoes release dust and ash which can alter the climate by blocking out the sun

• As well they can trigger mudslides and send lava down a mountainside

• This contour map represents a volcano

• The lava and ash flow would have to flow North due to the sharp drop in elevation on the Northward side

VOLCANOES

TSUNAMIS

• A tsunami is a large tidal wave that is generated by seismic waves released from an earthquake• Slab of crust is displaced along a fault

• Can travel up to 500-950 kilometers per hour

• Ways to mitigate tsunami damage:• Preserve dunes on beaches

Provide inland protection from tsunamis

• Build trenches to divert water

• Build seawalls to protect inland areas

TSUNAMIS

SINKHOLES

• A sinkhole is a natural depression on the Earth’s surface• Can be caused by collapse of underlying rock

SINKHOLES

• Mitigation:• Use filters Pump out water which dissolve underlying rock

• Careful inspection of bedrock

GROUNDWATER POLLUTION

• Groundwater-Water stored beneath the surface

• Becomes polluted when chemical seep into the ground and contaminate the aquifer• This can contaminate wells and a communities drinking water

FLOODING

• Flooding occurs over an area where water cannot seep into the soil• Soil is impermeable or saturated

• Mitigation: • Flood risk maps

• Don’t build homes on flood plains

• Redirecting waters through flood channels

FLOODING