Earthquakes don’t kill people, buildings do!!!

AGREE OR DISGAREE?

Write a 4 line response to this ……

Learning Objectives:

To understand the features of an earthquake.

To appreciate the differences in earthquake impacts around the world.

To understand how people can prepare for earthquakes.

In an average year, Approximately 12 million

earthquakes occur around the world

ONLY ABOUT 100 OF THESEHAVE A SIGNIFICANT IMPACT

What is an earthquakes• An earthquake is a sudden release of

energy, caused by the earths plates rubbing together.

• Where plates move against each other, pressure builds up between them. Eventually the pressure between these plates exceeds the friction holding them still and the earth’s plates jerk suddenly.

• This sudden release of energy sends out huge pulses known as ‘seismic waves’ which cause the ground to shake.

Features of an earthquake

Epicentre Seismic waves Fault /boundary Crust Focus

Effects of earthquakes

The effects of earthquakes can be divided into 2 categories:

• Primary effects – immediate consequences of the quake

• Secondary effects – long term consequences of the quake which come about days, weeks and even months after the actual quake

Primary effects

Secondary effectsBuildings collapse.

Fires: usually from ruptured gas lines. This was the main cause of death and damage after the San Francisco earthquake in 1906.

Tidal waves: A tidal waves caused by an earthquake is called a tsunami. They can travel very quickly across entire oceans, before engulfing land 1000's of miles away.

Landslides can often be triggered by earthquakes, causing huge amounts of material to be moved very quickly. This is actually what occurred just before the volcanic eruption on Mt. St. Helens. They are most likely to occur where the land is steep, saturated or weak.

Diseases can spread very quickly in the unsanitary conditions often left behind by massive earthquakes. Water becomes contaminated very quickly, and in Less Economically Developed Countries (LEDC's) especially; access for the medical services can be badly hampered by the damage caused by the quake. Roads and bridges being destroyed

and railway lines being buckled.

Liquifaction

• https://clipbank.atomwide.com/espresso/clipbank/servlet/asset?assetID=13453

• Watch the clip and add to your table. Ensure you explain what it is.

Not all earthquakes are the same!

“The stronger an earthquake is, the more damage it causes…”

Factors affecting damage caused by earthquakes

Big town

Small Village

Preparation?

Good response team

Basic response team

Factors affecting damage caused by earthquakes

Magnitude

Economic development (is the country an LEDC or MEDC)

Depth of earthquake(a shallow focus will cause more damage)

Strength of buildings

Time of day

Population

Preparation

Response

How are earthquakes measured?

• The power of an earthquake is known as its magnitude and is measured on a scale called the Richter Scale.(STICK IN COPY OF THE RICHTER SCALE)

• The magnitude of an Earthquake is measured using sensitive instruments called seismometers which measure the amount the ground shakes.

The Three P’s Policy

Predict

Protect

Prepare

All buildings must comply with strict earthquake planning regulations.

Existing buildings, roads and bridges should be strengthened.

Prepare disaster plans.

Organise and prepare hospitals and evacuation centres.

Organise emergency supplies.

There may be many pre-shocks before an earthquake that can be measured on a seismograph.

Animals often act strangely for examples dogs will howl before an earthquake.

Page 128-129

1. What can people do in earthquake prone areas?

2. Can scientists predict earthquakes?

Plenary: The ItemsFire Extinguisher 

First Aid Kit Swiss Army Knife

Plastic bucket 

Torch TV

Board games 

Matches Candles

Tin opener 

Spade Small tent

4 litres mineral water Water purifying tablets Toilet paper

Radio (battery operated) Sun screen Mobile phone

Disinfectant Tools including pipe wrench

Spare batteries

Credit Card 

Tinned food Dried food

Dust mask 

Money Blankets

Avalanche transmitter Spare batteries Camping gas and stove