Emergency Response to Hazards

Before

During

After

Risk Assessment

Prediction

Construction

Often it is not the earthquake that kills people, but the houses in which they happen to be in when the earthquake strikes. With earthquakes, the most dangerous building construction consists of bricks and unreinforced concrete blocks. Earthquake tremors causes these walls to collapse and cave in.

There is certainly much that can be done nowadays to make homes safer and more earthquake resistant, such as using lighter materials (timber, aluminium and carbon fibre) and building them on flexible frames with reinforced steel corner pillars

Prediction is knowing that a hazard event is shortly about to take place. Unfortunately, the prediction of earthquakes is still one of the great challenges facing the modern world. Scientists are still unable to predict exactly when they will occur.

What is needed is a system that can give a warning when an earthquake is about to happen. In other words, a system that:

  • gives people time to move into what are thought to be 'safe' locations. In most instances, this will mean leaving all buildings and moving out into open spaces.
  • puts the emergency services on immediate alert.

Risk is about the probability of a particular event happening and the scale of its possible damage

In order to assess risk, we need to be aware of three features of a particular type of hazard, as follows.

  • its distribution - where does it generally occur on the Earth's surface?
  • its frequency - how often does it occur?
  • its predictability - does the hazard always behave in the same way?

An inventive solution has recently been put forward by a Japanese company: the levitating or floating home. During stable times, the house sits on a deflated air bag. When sensors detect a tremor, they switch on a compressor within seconds. The whole house lifts three centimetres of the ground.

Warning systems

Remote sensing and GIS

After an earthquake, different types of emergency services specialise in:

  • releasing people and bodies trapped in collapsed buildings
  • using lifting gear and diggers to clear away rubble and storm surge debris
  • restoring basic services such as water, sewage, gas, electricity and communications
  • providing medical help and counselling victims
  • organising the distribution of emergency rations of food, water and clothing
  • setting up temporary shelters for people made homeless
  • providing transport for emergency supplies - this is often done by the armed forces

Once an earthquake has started, equipment such as seismometers, accelerometers, computers and satellites are able to raise the alarm and transmit a warning to those areas that are likely to be affected. Such alarms are most useful to the emergency services.

Satellite images are increasingly being used in connection with earthquakes. For example, images of the affected area immediately after the earthquake can provide valuable information for search and rescue operations. In earthquake zones, satellite images are systems (GIS) about various aspects of the earthquake hazard. For example:

  • mapping the degree of seismic (earthquake) risk
  • detailing the locations of settlements, transport networks and economic activities within those high-risk areas
  • identifying areas where landslides are likely to be triggered by an earthquake

Education

The aim here is to make sure that people know what they should do both during and after an earthquake. This includes knowing where to find safe open spaces and locations beyond the reach of earthquakes. In Japan, and in many other high-risk countries, earthquake drills are commonplace in schools and colleges.