Geohazards

In your ISN on page 88 and 89 copy ALL text in RED Directions In your ISN on page 88 and 89 copy ALL text in RED

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

landslides 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 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

http://video.nationalgeographic.com/video/101-videos/landslides

Earthquakes 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

https://www.youtube.com/watch?v=9uMtkrrNgzQ

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

volcanoes 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

What do you think the best way is to prepare for volcano damage? http://www.telegraph.co.uk/news/world news/europe/iceland/11140736/Specta cular-drone-footage-of-erupting- Icelandic-Volcano.html

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(310 – 590 mph!)

Ways to mitigate tsunami damage: tsunamis 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

A sinkhole is a natural depression on the Earth’s surface 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

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

Flooding Mitigation: Flood risk maps Don’t build homes on flood plains Redirecting waters through flood channels