Prediction,monitoring and repsonses

• Prediction: forecasting the occurrence of an earthquake of a particular intensity in a specific location within a specific time range.
• Name the 3 different types of prediction + explain what they are:

  1. Long-range prediction--> Forecasting events years in advance.
  2. Medium-term prediction --> Forecasting events a few months to a year before they occur.
  3. Short-term prediction --> Forecasting events within hours to days in advance.
• Earthquakes are almost impossible to predict. Microquakes may give some indication, but the magnitude and time range cannot be predicted as they are random. Though scientists can often forecast which areas are at risk from seismic hazards.
• No method of prediction has yet proved to be reliable
• • The United States Geological Survey have made forecasts about the chances of an earthquake in the Los Angeles area:

  • Within the next 30 years there is a 60% probability of a 6.7 magnitude earthquake
• What are the different ways to predict earhquakes (though still unreliable)?

  1. Monitoring Deformation
  2. Observing Animal Behaviour
  3. Tempture change
  4. Measuring Pre-Cursor earthquakes / forshocks
  5. Measuring groundwater levels
  6. Radon Emissions
• Name the 3 different methods of measuring the magnitude of an earthquake:

  1. The Richter Scale
  2. Moment Magnitude Scale
  3. Mercalli Scale
• What are the basics of the Richter scale?

  • It is a logarithmic scale
  • Interpreters the distance moved by the vibrating pen on a seismograph
  • Scale starts at 0 and goes to 10
  • The energy that is released is proportional to the magnitude, so that for each unit increase on the scale, the energy released increases by approximately 30 times more.
• What are the basics of the Moment Magnitude Scale (MMS)?

  • Geologists use the MMS more as it identifies energy released.
  • One which is reported on the news when an earthquake occurs.
  • A logarithmic scale
  • Based on the total moment release of an earthquake. Moment is a product of the distance a fault moved and the force required to move it.
  • This scale is more accurate and capable of measuring magnitudes over 8.
• What are the basics of the Mercalli Scale?

  • Measures the intensity of the event and its impact (through observations)
  • A 12 - point scale
  • A 12 on the the Mercalli scale is equal to an 8.5 on the Richter
  • I = Not felt when only seismographs can measure the impact (can’t be felt or seen by humans)
  • XII = extreme, results in complete destruction.
• Largest ever recorded earthquake was a 9.5 in Chile in 1960.
• • Magnitude is the amount of energy released.
  • Intensity is the severity of ground shaking in a particular place based on the effects on humans, buildings, and the environment.
• Name the different ways to protect themselves from seismic hazards:

  1. Creating hazard resistant structures
  2. Implementing fire prevention
  3. Education
  4. Training Emergency services
  5. Land use planning
  6. Insurance
  7. Aid
  8. Tsunami Protection
• Name 3 ways buildings are made hazard-resistant:


  • Placing large concrete weights on top of a building.
  • Putting large rubber shock absorbers in the foundations of a building.
  • Cross Bracing
• One way buildings are created to be hazard resistant is:

  By placing large concrete weights on top of a building. These weights can move due to computer programming. During a seismic event, they will move in the opposite direction of a force. Preventing the building from collapsing due to it balancing out.
• Buildings are created to be hazard resistant by:

  Putting large rubber shock absorbers in the foundations of a building. Which allows the building to move slightly. This flexibility and controlled movement helps the building withstand the forces generated by earthquakes. Without this ability, buildings could experience catastrophic structural failures.
• Buildings are created to be hazard resistant by:


  Implementing Cross Bracing: Using two steel beams to create an X pattern that increases a building's load capacity and stability during seismic events.
• By comparing the impacts of seismic events in California to Armenia, the benefits of making structures hazard resistant are clear:

  • 1989 Loma Prieta earthquake (7 MMS) = in California there were 63 deaths as their buildings were earthquake proof.
  • Compared to the 1988 (7 MMS) in Armenia, = had 25,000 deaths as many buildings collapsed due to soft foundations and no earthquake proofing features.
• Fire prevention helps mitigate the impacts of seismic events. One method of fire prevention is:

  A Smart meter --> They have been developed to cut off gas if an earthquake of sufficient magnitude occurs.
• An example of where fire prevention is used to mitigate seismic events is:

  In Tokyo, gas companies have seismic information to know who's gas to turn off during an event. Causing a reduction in the number of fires.
• For many years, education was the main way loss of life during seismic events could be minimised.
• How does education protect people from seismic events?


  • Instructions are issued by authorities on how to prepare for seismic events by securing homes, appliances, and heavy furniture and assembling “earthquake kits.”
  • Children have earthquake drills at school, as do people in work places.
• Examples of places that use education as a method to minimise the impacts of an earthquake?

  • Government offices and many companies in Japan observe Disaster Prevention Day (1st of September), which marks the anniversary of the Tokyo earthquake in 1923.
  • After the Loma Prieta event in California ,1989, the American Red Cross issued a list of supplies that people should keep at home in case of an earthquake. This list included water supplies, foodstuffs, clothing, bedding, first aid kits, tools, radios, etc
• Land use planning

  • The most hazardous areas in the event of an earthquake can be identified and then regulated in terms of land use
  • Certain types of buildings should be put in areas of low risk, e.g., schools and hospitals.
  • It is also important to have sufficient open spaces, as this forms safe areas away from fires and aftershock damage to buildings.
• Insurance (manage losses)

  • In richer areas, people are encouraged to take out insurance to cover losses. Though for the individual this is very expensive (con).
  • E.g., in the Kobe earthquake in Japan in 1995, only 7% of people affected were covered by their insurance.
• Aid (manage losses)

  • Most aid to poorer countries has generally been for immediate responses. Providing medical services, tents, water purification equipment, etc.
  • Long term aid is more problematic; it is something that is needed for the reconstruction of the built environment and the redevelopment of the economy.
• Tsunamis cannot be entirely predicted, even if the magnitude and location of an earthquake are known. Though certain automated systems can be installed to give warnings to areas:
• Tsunami warning systems:

  The best warning systems use bottom pressure sensors attached to buoys, which constantly measure the pressure of the overlying water column.
• What's an example of a tsunami warning system?

  The pacific warning system is based on Hawaii. It monitors earthquake activity and issues warnings to countries around the Pacific edge if tsunamis are likely to occur.
• Tsunami protection:

  Some countries have built protection walls up to 12 m in height, though these are usually costly and ineffective as large tsunamis overwhelm them.
• Prevention: Trying to prevent an earthquake is thought to be impossible. Though we can prevent human induced quakes caused by fracking.
• Protection: preparing for the event by modifying the human and built environments in order to decrease vulnerability. This includes attempts to modify losses by insurance and aid.