Earthquakes: an introduction

Hindu Mythology

Japanese Mythology

I magine that you are an Australian living hundreds and hundreds of years ago. You have no scientific understanding of the earth and how earthquakes occur. A s an Australian, how would you explain this phenomena?

Formation of the Earth

Continental Drift

Evidence Other than the jigsaw pattern of the continents there are two strong pieces of evidence to support the theory of continental drift 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 Scale Richter Magnitudes DescriptionEarthquake effectsFrequency Less than 2.0MicroMicro earthquakes, not felt. 8,000 per day MinorGenerally not felt, but recorded. 1,000 per day MinorFelt, but rarely causes damage. 49,000 per year LightNoticeable shaking of indoor items, rattling noises. Significant damage unlikely. 2,200 per year ModerateCan cause major damage to poorly constructed buildings over small regions. At most slight damage to well- designed buildings. 800 per year StrongCan be destructive in areas up to about 160 kilometres (100 mi) across in populated areas. 120 per year MajorCan cause serious damage over larger areas. 18 per year GreatCan cause serious damage in areas several hundred miles across. 1 per year GreatDevastating in areas several thousand miles across 1 per 20 years EpicNever 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 Kong Macao Taiwan Vietnam Thailand Mongolia Bangladesh Nepal India Pakistan