Preparing for Earthquakes (Edexcel IGCSE Geography)
Revision Note
Warning & evacuation
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
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
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)
Examiner Tips and Tricks
Remember with earthquakes preparation is essential because at the moment they are impossible to predict.
Case Studies: Nepal & Japan
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
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