Measuring risk + risk management Flashcards
State reasons on why people live in areas prone to earthquakes and volcanic eruptions?
people live in areas prone to earthquakes and volcanic eruptions due to:
Geothermal energy
Mining
Farming
Tourism
Family, friends and feelings
How is Geothermal energy a reason on why people live in areas prone to earthquakes and volcanic eruptions?
In volcanically active areas, geothermal energy is a major source of electrical power: steam is heated by hot magma in permeable rock, then boreholes are drilled into the rock to harness the super-heated steam to turn turbines at power stations. It is renewable (will not run out) and will reduce greenhouse gases and climate change.
Hellisheidi power plant is the largest geothermal power station in Iceland and the second largest in the world, producing 30% of Iceland’s total electricity.
How is Farming a reason on why people live in areas prone to earthquakes and volcanic eruptions?
Lava and ash erupting from volcanoes kill livestock and destroy crops and vegetation. After thousands of years, weathering of this lava releases minerals and leaves behind extremely fertile soil, rich in nutrients. Land can be farmed productively in these areas to provide a source of food and income.
IMPORTANT: Volcanic soils are found on less than 1% of the earth’s surface, but support 10% of the world’s population.
How is Mining a reason on why people live in areas prone to earthquakes and volcanic eruptions?
Settlements develop where valuable minerals are found, as jobs are created in the mining industry.
It is not just dormant and extinct volcanoes that are mined, but also active volcanoes.
Kawah Ijen is an active volcano in East Java, Indonesia. Its crater is one of the biggest sulphuric lakes in the world. Sulphur is sold to bleach sugar, make matches, medicines and fertiliser. This is an extremely dangerous job.
But miners can earn up to $6 a day, which is more than at a coffee plantation, so workers continue to risk their lives.
How is Tourism a reason on why people live in areas prone to earthquakes and volcanic eruptions?
Tourists visit volcanoes for the spectacular and unique views, relaxing hot springs, adventure and a sense of danger for thrill seekers.
More than 100 million people visit volcanic sites every year. The money they generate benefits the locals and the countries they are in.
How is Family, Friends and Feelings a reason on why people live in areas prone to earthquakes and volcanic eruptions?
People do not wish to leave because their friends and family are there. It is often cheaper and easier to stay, especially when the risks may not be perceived as dangerous enough, or residents are in denial that a disaster may occur.
State how can the effects of volcanic eruptions and earthquakes be reduced
The effects of volcanic eruptions and earthquakes be reduced by:
Planning
Monitoring
Prediction
Protection
How can prediction reduce the effects of earthquakes
Prediction can reduce the effects of earthquakes.
The location of earthquakes and their times are mapped to look for patterns, and from the results, predictions are made about when and where the next earthquake might occur.
Experts can use seismometers to monitor earth tremors. Experts know where earthquakes are likely to happen, however it’s very difficult to predict when they will happen
For example:
Along the San Andreas fault in California, USA, scientists have some of the most advanced technical equipment and education in predicting earthquakes – but they too cannot be exactly sure of when or where an earthquake may strike.
How can protection reduce the effects of earthquakes
Protection can reduce the effects of earthquakes.
Protection involves constructing buildings so that they are safe to live in and will not collapse. Some examples of building improvements are:
Rubber shock absorbers in the foundations to absorb the earth tremors.
Steel frames that can sway during earth movements.
Open areas outside of the buildings where people can assemble during an evacuation.
Low cost methods, such as wire mesh retrofitting, are used in rural areas and developing countries. These are affordable and appropriate to the resources and people living there.
Lightweight roofs and safety glass designed to reduce damage and injury.
How can planning reduce the effects of earthquakes
Hospitals, emergency services and residents practise for an earthquake in earthquake-prone countries. They have drills in all public buildings so that people know what to do in the event of an earthquake. This helps to reduce the impact and increases people’s chance of survival.
Earthquake drills happen in Japan on the 1st of September every year.
Having well equipped emergency service teams who are well trained also increases a country’s ability to cope
How can monitoring reduce the effects of earthquakes
Radon gas detection is used to measure radon gas which can escape through cracks in the surface of the Earth. Seismometers and GPS devices are used to measure foreshocks (smaller earthquakes that happen before large earthquakes).
Animal behaviour is also monitored as they are thought to act strangely when an earthquake is about to happen.
How can MONITORING/predicting reduce the effects of volcanoes
seismometers – used to measure earthquakes occurring near an eruption
tiltmeters and global
positioning systems (GPS) satellites – these devices monitor any changes in landscape, eg volcanoes tend to swell near an eruption
thermal imaging – this allows a camera to monitor heat sources within the crust or volcano, it may help predict the onset of an eruption
infrared camera imagery – these images can potentially show the magma chamber and any build-up of hot gases, steam or lava
monitoring gases escaping from a volcano using robots called spiders – often there is an increased release of sulphur dioxide near an eruption as the magma gets closer to the surface
measuring temperature – volcanoes become hotter when magma starts to rise through the main vent
looking at previous eruptions – scientists can identify patterns of activity
How can planning reduce the effects of volcanoes
Hazard maps can be used. Hazard mapping allows local areas to limit access to the danger zones and prevent buildings near to potential hazards from being built.
Exclusion zones can also be created, where no-one is allowed in them before, during or after an event.
Local people can also be educated about actions they can take to reduce the risk of loss of life or injury. People are taught that if they are unable to be evacuated what they should do to protect themselves, e.g. go indoors to avoid falling ash and rock.
How can protection reduce the effects of volcanoes
evacuation is the only real way of reducing the risks associated with volcanic eruptions.
How can prediction reduce the effects of volcanoes
By monitoring the movement of tectonic plates and changes in the surface of the volcano, scientists can predict the likelihood of a volcanic eruption and forecast which areas should be prepared for one.
Predicting when a volcano is at risk of eruption allows time for evacuation plans to be initiated.
