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Earthquakes menu
Earthquakes - An Introduction
Cause of Earthquakes

Effects of Earthquakes
Measuring Earthquakes

What factors influence the effects and response to tectonic activity?

Case Studies
The Kobe Earthquake 1995
The Turkish Earthquake 1999
Earthquakes in California
Gujarat Earthquake 2001

Haiti Earthquake 2010

Japanese Earthquake 2011

Well trained rescue teams can reduce the impact of earthquakes ( Source - J. K. Nakata - US Geological Survey)

What factors influence the effects and response to tectonic activity?


Earthquakes tend to have a greater impact in Less Economically Developed Countries (LEDCs) than More Economically Developed Countries (MEDCs).

Buildings in More Economically Developed Countries (MEDCs) are more likely to withstand an earthquake, because they may be designed to withstand tremors. They may have seismic isolators (e.g. Japan) or deep foundations (e.g. USA). In 1995 an earthquake measuring 7.2 on the Richter scale hit the Japanese city of Kobe. Only 5000 people were killed.

However, in LEDCs the buildings are often of poor design because of cost. This is one reason why earthquake damage in LEDCs is usually greater. For example in 1999 an earthquake measuring between 6.8-7.0 on the Richter Scale killed 17 000 people in Turkey.

MEDCs are more likely to have response plans available. In Japan school students practice an earthquake drill on the 1st September every year. Emergency services are well trained in responding to a tectonic hazard. In contrast LEDCs tend to lack disaster response plans.

LEDCs often have to rely on aid from MEDCs to assist in responding to earthquakes. Aid can come in many forms e.g. medical facilities, tents, rescue teams etc. Aid can take anywhere up to 3 days to arrive. This reduces the chance of survival for many people injured or trapped beneath buildings.

Rural and Urban areas
Population density also affects the impact of an earthquake. Earthquakes can be a devastating phenomenon when they hit densely populated areas. Their effect can be greatly reduced in more sparsely populated areas.

Distance from the epicentre
The closer the epicentre the stronger the earthquake. Therefore earthquakes that have epicentres close to major urban areas tend to cause more problems than those that occur some distance from urban areas.

Emergency response
Lack of emergency services and poor communication links in Less Economically Developed Countries mean that people are not rescued as quickly, or cared for as well, as they would be in a More Economically Developed Country.

Time of day
Night time earthquakes can make it more difficult to rescue people immediately after an earthquake. However, there are few people on the street, in public buildings and at work.

Time of Year
Earthquakes can result in higher fatalities if they occur in times of cold weather.

Surface type
The type of soil or rock that an area is built on affects the impact of the earthquake. Soils that contain a large amount of water can turn to liquid causing the buildings to sink. This is called liquefaction.
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