Preparing for Earthquakes (Edexcel IGCSE Geography)

Warning & Evacuation

Spec point — 4GE1-S3.044

• Accurate prediction of earthquakes is not currently possible but monitoring is

• Many different methods of monitoring are being used to find possible prediction methods:

  • Tiltmeters- which monitor ground changes
  • Clusters of small earthquakes
  • Changes in radon gas emissions
  • Changes in animal behaviour such as toads
  • Remote sensing of ground movement using satellites

Building Design & Preparation

Spec point — 4GE1-S3.044

• Countries can prepare for earthquakes in several ways:

  • Building design and earthquake-resistant structures
  • Land use planning
  • Earthquake drills
  • Emergency planning

Building design

• In developed countries building design and engineering are commonly used to reduce the impact of earthquakes

• Building regulations and codes require new buildings to include earthquake-resistant features:

  • Shutters on windows prevent falling glass
  • Small windows
  • Reinforced walls
  • Cross-bracing of steel frames
  • Foundations sunk deep into the bedrock
  • Frames which sway with the earthquake tremors
  • Rubber shock absorbers to reduce tremors moving through the building

Land use planning

• Land use mapping involves mapping areas most at risk from earthquakes
• Once the areas are mapped planning can ensure that valuable services such as the fire service and hospitals are not built in high-risk areas
• Densely populated housing can also be located away from high-risk areas

Drills and education

• In many countries, earthquake drills are regularly carried out

• The drills help people to prepare for what to do in an earthquake to protect themselves

  • People are more likely to survive if they know what to do in the event of an earthquake
  • Drop, cover and hold on is the advice given to people to protect themselves if indoors

• Education about how to prepare homes means that people are less likely to be injured by falling objects and furniture

Remote Sensing & GIS

Spec point — 4GE1-S3.044

Remote sensing and GIS

• Remote sensing of the Earth's surface by satellites such as Sentinel 1 provides data about changes in ground movement

• Geographic Information Systems (GIS) provides layers of data such as:

  • vulnerable areas
  • land use
  • infrastructure such as roads

• GIS data is then used to assist with land use planning

• The data can also be used by emergency services to manage the impacts of earthquake including:

  • the risks to population, buildings and infrastructure
  • recommending mitigation for future earthquakes
  • search and rescue prioritisation
  • informing decisions about where resources should be directed

Worked Example Study Figure 1b which shows an earthquake-resistant building

Identify the element of building design in box X which makes it earthquake resistant

(1 Mark)

• Answer

  • The feature identified in the image is the cross bracing which makes the building less likely to collapse. Any of the following answers would be accepted

    • Cross bracing (1)
    • Reinforced concrete (1)
    • Concrete exoskeleton (1)

Exam Hint Remember with earthquakes preparation is essential because at the moment they are impossible to predict.

Case Studies: Nepal & Japan

Spec point — 4GE1-S3.044

Case Study

Nepal - A developing country

• Nepal is one of the poorest countries in the world
• GDP per capita in 2015 was US$3,332
• The country is **politically unstable **with a civil war between 1996 and 2006
• Earthquake experts view Kathmandu as one of the most dangerous places in the world in terms of earthquake risk

Preparations before the 2015 earthquake

• In 1997 the Nepali government created the** Kathmandu Valley Earthquake Risk Management Project (KVERMP)** this included;

  • The School Earthquake Safety Programme (SESP) provided funding to schools for earthquake drills
  • Training to make buildings more resistant to earthquakes
  • Earthquake Safety Day

• Allocation of 83 open spaces around Kathmandu to be used as camps for displaced populations where they would be supplied with shelter, food and medical services

• Improved the 1994 National Building Code and trained building inspectors

• In 2009, the government set up a National Strategy for Disaster Risk Management

• In 2010 a National Emergency Operations Centre was set up to coordinate the humanitarian response and restoration of the infrastructure

• Nepal Red Cross Society maintained 12 warehouses with stocks of emergency supplies

Issues with the preparations

• The earthquake education was mainly in urban areas so people in rural areas did not have drills or knowledge about what to do when the earthquake struck
• There are 121 recognised languages as well as Nepali (the official language) which are spoken in Nepal this makes communication of earthquake advice and education difficult
• There were not enough emergency supplies to begin with
• The building code was often ignored and so many buildings were still not earthquake-resistant
• Due to political instability, the national strategy and operations centre were not as effective as they should have been
• The emergency supplies of the Nepal Red Cross were not enough for the scale of the disaster

Case Study

Japan - A developed country

• Japan is one of the wealthiest countries in the world
• GDP per capita in 2011 was US$48,168
• Japan is one of the most seismically active places in the world with 20% of earthquakes over magnitude 6.0 happening there

Preparations before the 2011 earthquake

• Earthquake drills are practiced regularly so that people know exactly what to do during an earthquake event and immediately afterwards

• Households are encouraged to have an emergency survival bag packed and ready at all times

• Many buildings are designed to be earthquake-resistant

  • Building codes were further tightened after the Kobe earthquake in 1995
  • Over 80% of buildings in Tokyo are earthquake-resistant

• Sea walls between 3-10m built in some coastal areas

• Breakwaters off the coast at Kamaishi and Ofunato Bay

• Trains automatically stop when an earthquake is detected, to avoid derailments

• Nuclear power stations automatically shut down

• There is a tsunami warning service with 180 seismic stations and 80 water-based sensors

  • Warnings are issued via

    • phone
    • television
    • sirens
    • loudspeakers

  • The warning system costs about US$20 million a year

Issues with the preparations

• People did know exactly what to do in the earthquake but were not as prepared for the tsunami
• Many people do not have an emergency survival bag
• Many buildings survived the earthquake but not the tsunami
• The tsunami overtopped the sea walls
• There was an issue restoring the cooling system at the Fukushima nuclear power plant leading to radioactive contamination in the surrounding area
• People ignored the tsunami warning as they thought they would be protected by the sea walls