What factors influence the effects and response to tectonic activity?

HICs and LICs

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 more significant. For example, in 1999, an earthquake measuring between 6.8 and 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 every year on the 1st of September. 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 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 significantly reduced in more sparsely populated areas.

Distance from the epicentre

The closer the epicentre, the stronger the earthquake. Therefore, earthquakes with epicentres near 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 LICs mean that people are not rescued as quickly or cared for as they would be in a HIC.

Time of day

Night-time earthquakes can make rescuing people immediately after an earthquake more difficult. However, few people are 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 an area is built on affects the earthquake’s impact. Soils containing a large amount of water can turn liquid, causing the buildings to sink. This is called liquefaction.