Earthquakes: an introduction

Hindu Mythology

Japanese Mythology

Imagine that you are an Australian living hundreds and hundreds of years ago. You have no scientific understanding of the earth and how earthquakes occur.

As an Australian, how would you explain this phenomena?

Formation of the Earth

Continental Drift

EvidenceOther than the jigsaw pattern of the continents there are two strong pieces of evidence to support the theory of continental drift....

1.The rocks found in the lower/older layers of mountain chains running across South Africa and Argentina are the same, despite being divided by the Atlantic Ocean.

2.Scientists have also found identical fossilised remains of plants and animals on both Africa and South America.

Plate Tectonics

Take out your Atlas!!• On the blank map provided locate

and label all of the world’s tectonic plates, and show the direction of movement of each plate.

• Then locate and label the worlds earthquake and volcano zones on the map.

• Remember to use BOLTSS!

Plate Boundaries• Plate boundaries exist on the borders of

tectonic plates.• Tectonic plates are constantly moving,

they may crash into each other, slide past each other or move apart.

• Where they interact, along their margins, important geological processes take place, such as the formation of mountain belts, earthquakes, and volcanoes.

Earthquakes generally occur at plate boundaries that:

• Are pulling apart• Scrape past one another• Slide under one another

•

• Boundary of the Eurasian and North American Continental Tectonic plates.

Richter ScaleRichter Magnitudes

Description Earthquake effects Frequency

Less than 2.0 Micro Micro earthquakes, not felt. 8,000 per day2.0-2.9 Minor Generally not felt, but recorded. 1,000 per day3.0-3.9 Minor Felt, but rarely causes damage. 49,000 per year4.0-4.9 Light Noticeable shaking of indoor items, rattling noises.

Significant damage unlikely.2,200 per year

5.0-5.9 Moderate Can cause major damage to poorly constructed buildings over small regions. At most slight damage to well-designed buildings.

800 per year

6.0-6.9 Strong Can be destructive in areas up to about 160 kilometres (100 mi) across in populated areas.

120 per year

7.0-7.9 Major Can cause serious damage over larger areas. 18 per year8.0-8.9 Great Can cause serious damage in areas several hundred miles

across.1 per year

9.0-9.9 Great Devastating in areas several thousand miles across 1 per 20 years10.00+ Epic Never recorded; see below for equivalent seismic energy

yield.Rare (unknown)

Hazards• Ground shaking• Flooding: dams and levees can be ruptured

by the shaking• Fire: Shaking can cause main gas lines and

power lines to break.• Tsunami:(which we will be looking at later)

caused by earthquakes that occur under the sea.

• The majority of earthquake related deaths are caused by collapse of buildings, although the other hazards can be a serious issue as well.

2008 Sichuan Earthquake

Tremors• Tremors from this

earthquake were not just felt in China, many surrounding countries also felt the affects of this massive earthquake.

Using your Atlas, find Sichuan province (in China)

• Locate the countries listed below• Draw lines from Sichuan province

to the countries• Using the map ‘scale’ find the

country that is furthest away from Sichuan Province.

Hong KongMacaoTaiwanVietnamThailandMongoliaBangladesh NepalIndiaPakistan