What factors influence the effects and response to tectonic activity?
Earthquakes tend to have a greater impact in low income countries (LICs) than higher income countries (HICs).
Buildings in HICs 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 LICs the buildings are often of poor design because of cost. This is one reason why earthquake damage in LICs 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.
HICs 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.
LICs often have to rely on aid from HICs 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.
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.
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.
Lack of emergency services and poor communication links in LICs mean that people are not rescued as quickly, or cared for as well, as they would be in a HIC.
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.
Earthquakes can result in higher fatalities if they occur in times of cold weather.
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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