Risk posed by Tectonics over time. Flashcards
Introduction?
=> Define what risk is.
=> Categories of risk.
=> Define EQs and Volcanoes, list their secondary hazards.
=> Define time (last 30 years + reference to geological scale of time).
Paragraph 1: Population growth?
=> Increasing population (8.1bn from 6.1bn in 2000). -> More will be harmed if the same hazard.
=> Increasing vulnerable population (science, better healthcare), longer life expectancy, more likely to suffer risk and fatalities and death. -> E.g in Japan Tonhoku EQ -> 2/3 of victims were over 60 years old. Could not use technology to evacuate.
=> WHEREAS Sparsely populated, low vulerability, low risk -> E16 in Iceland, saw no deaths.
=> High population growth also drives up land prices. -> Forced to relocate to tectonically active places. -> Put at greater risk from being affected. -> New Zealand, high costs in cities like Auckland. -> Have had to settle in hazard prone areas.
=> Example of Christchurch EQ. - 5th most deadliest EQ in the country.
=> RISK HAS INCREASED.
Paragraph 2: Globalisation.
=> Globalisation is the idea that the world has become increasingly connected and interdependent on one another through technology and foreign trade.
=> Thus hazards increase economic risk, as if one country is impacted by a hazard, this can have an international affect, thus increasing the international reach and risk.
=> E.g after the earthquake, and secondary hazard of a mega tsunami of 40m -> destroyed ports of Japan and disrupted normal production. Companies that relied on Japan for overseas parts had their manufacturing lines disrupted like Sony.
=> Interdependence also extends to LIDCs. -> After the E16 EQ. -> Global travel air ban for 8 days due to 11,000 m ash plume produced. -> Over 50,000 Kenyan farmers had become temporarily unemployed. 20% of economy based on green vegetables and fresh flowers, which it could not export.
=> However could be argued that this was circumvented by supermarkets who had a contingency plan! Flew to spain and then use of road haulage.
=> BUT ultimately still increases economic risk, Kenya did not have a plan on its own, and would have been unable to export without the external help.
Paragraph 3: Perception of risk.
=> People have a low perception of risk, which can increase their risk when they are actually faced with a tectonic hazard as they are less likely to be prepared as they saw no previous risk. -> Mt Etna is an active volcano in Italy, which the population have become accustomed to, and so do not worry as much, the stratovolcano erupting several times a year.
=> ADDITIONALLY, they may also have a low perception of risk due to also a limited population memory of the disaster as seen with the DRC, Goma. -> Not prepared for the hazard. This is because a small EQ around the area has only occurred every 1000 years. -> 15% of homes were destroyed, no preparation, 350,000 dependent on aid.
=> HOWEVER, it can be argued that their perception of risk does not increase their actual risk as few people have died from the volcano. -> Only 77 deaths can be attributed with certainty to Mt Etna.
=> BUT risk and vulnerability does not have to take a social form, can also be economic. -> Mt.Etna has caused widespread damage and destruction. In 2001, it caused $3.1 million worth of damage.
=> Risk has increased.
Paragraph 4: Frequency and magnitude?
=> Risk from tectonic hazards has not increased. -> Over a wider geological scale, the number of volcanic eruptions or earthquakes has not increased or decreased.
=> Whilst on data, this number has increased over time (we now have 400 EQs daily), this is because more disasters have been reported and recorded as people have made increasing use of technology and scientific method and research, and advances in EQ detection technology. -> Italy has a sophisticated monitoring system.
=> FURTHERMORE, magnitude has not necessarily increased either and risk in the shorter time period has not changed either. -> In 2010, there was only 1 EQ of over magnitude 8. In 2015, there was also 1 EQ over magnitude 8. Thus, people are receiving the same exposure that they did before.
=> HOWEVER, despite this, trends in the last 30 years show that the number of people that are affected by disasters has increased. One reason is due to poverty. -> Choosing economic security over physical security. In Goma, more than 80% of people live on less than $1.25 a day.
=> Transform faults, never well mapped. -> When they collide, they lead to an onward distribution of energy, and further fracture, increasing risk.
Risk has increased.
Conclusion?
The risk has increased over time, including even in recent years. Though actual hazards levels have remained consistent over time, the rapidly changing nature of the world has increased its risk, as the global population has become more at risk and in danger of being affected by a tectonic hazard.
