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sec 4 3.1, sec 4 3.4, sec 4 3.3, sec 4 3.2 - Coggle Diagram

- - - - reduce disaster risks as tectonic hazards occur
        
        tsunami and earthquake early monitoring and warning systems enable for timely evacuations to reduce the potential loss of lives
      - manage the disaster risks after the tectonic hazards occur
        
        insurance coverage, which offers financial payouts to rebuild when properties are damaged or destroyed
        
        this brings about quicker recovery from the impacts of a tectonic hazard
      - prevents disaster risks before the occurrences of tectonic hazards
        
        designing hazard resistant buildings to ensure that structures can withstand hazards and do not collapse easily
        
        taipei 101 is a skyscraper built in an earthquake prone zone. It has a weighted damper near the top of the building to balance out ground shaking from earthquakes. This reduces the sway of the building during an earthquake and therefore the threat of the building collapsing
- - - - however, there are developing countries that are able to reduce disaster risks through investment and planning
        
        reducing disaster risk is a cost-effective investment in preventing future losses, therefore contrubuting to sustainable development
        
        the aditional investments to reduce disaster risks are often smaller than the costs incurred from disasters
        
        with less losses, the money to rebuild will be minimised, adn development gains achieved will not be lost, thereby contributing to sustainable development
        
        eg. the Mw 8.8 Chile earthquake in 2010 resulted in less building damage and a lower casualty count of about 500 compared to the Haiti earthquake which had a lower magnitude , due to Chile's modern earthquake resistant buildings
- - - - eg. during the 2011 Tohoku Japan earthquake and tsunami, nearly all 3,000 students in Kamaishi city survived. The students were evacuated to higher ground immediately after the earthquake struck, saving them from the tsunami caused by the earthquake
      - eg. in 2010, after a warning of Mount Merapi's imminent eruption was issued by scientists, Indonesia's authorities organised massive evacuation efforts that comprised more than 700 evacuation centres. The quick and massive evacuation efforts were credited for saving more than 10,000 lives
  - - - eg. in the 2020 Aegean Sea, Turkey earthwuake Mw 7.0, more than 8,000 search, rescue and first aid teams were deployed and over 106 people were rescued
- - - - eg. immediately after the 2015 Nepal Mw 7.8 earthquake, the government and opposition parties created a new public body, the National Reconstruction Authority to oversee the rebuilding. However due to political disagreements, it took nine months to appoint a leader for the NRA, hence hindering recovery works in the country.
      - eg. in the Philippines, only 10-20% of buildings are insured against earthquakes, because of the high insurance costs for building owners
  - - - eg. during the 2010 Mw 7.0 Haiti earthquake, Haiti's lack of resources hampered the disaster management efforts. There was a lakc of ambulance's to transport the injured, and heavy machinery to removfe rubble from collapsed buildings. Thus, the rescue team spent many hours removing tons of rubble manually with hammers or rods to pull the trapped people under collapsed buildings
- - - - eg. Bangladesh, a developing country, lies along a plate boundary. As about 30% of Bangladeshis lie below the poverty line, most of the country's resources are devoted to economic development. It has been found that 21% of the buildings in the capital, Dhaka, are easily damaged and unreinforced. 77% of the buildings are reinforced but have not been designed to resist earthquakes. This makes Dhaka very vulnerable to the impacts of earthquakes
  - - - eg. the 2010 Haiti earthquake, Mw 7.0 resulted in over 220,000 deaths. This is because the community in Haiti was unable to organise themselves as therer were no measures put in place to educate Haitians on what to do during a disaster. It had no network of community healthcare workers, whihc limited the medical and emergency response and poor law enforcement led to looting becomign prevalent as the need to survive became prevalent. There was chaos and unrest as survivors found it hard to take care of themselves and recover from disaster
- - - - aims to reduce the community's exposure to tectonic hazards by controlling and minimising development in high risk areas. This decreases the potential loss of lives and damage to properties. Using hazard maps, strict guidlelines to control developments are implemented. Hazard maps identify areas at risk and uses data on past earthquake events to suggest the level of risk based on the likelihood of disaster occurring and indicate the likely extent of disasters.
        
        eg. after the 1933 tsunami in Japan, land use planning was implemented, residential land use in coastal areas such as the Touni-hongo village, were shifted to higher ground. When the 2011 Tohoku tsunami struck, the houses on higher ground were not destroyed
    - - monitoring and warning systems are a set of devices used to detect seismic waves and ground deformation. They can help make predictions and send warnings about potential hazards. The warnings enable people to evacuate to a safer place, reducing their susceptibility to tectonic hazards. For instance, the Earthquake Early Warning systems use a netowrk of monitors and sensors that detect seismic waves during an eathquake. Alerts are sent to smart devices to inform the people of when the seismic waves might reach them. This provides an advance warning for people. This is critical for saving lives as it gives people and authorities time to respond and evacuate quickly. Earthquake sensors identify risk areas, allowing aid to be directed where most needed.
        
        eg. during the 2011 Tohoku japan Mw 9.0 earthquake, monitoring and warning system detected strong tremors, and a signal was sent out to stop the bullet trains. This saved the lives of thousands of passengers
    - - earthquake resistant buildings designs that can withstand ground shaking include shock absrobers and dampers in buildings to absorb vibrations, reinforcing buildings with cross diagonal braces to retain the building's shape during earthquake events. These prevent the building from swaying too much, reducing the vulnerability of the building from collapsing. People are less likely to get trapped in collapsed buildings, leading to less injuries and less loss of lives.
        
        eg. Taipei 101 is a skyscraper built in an earthquake prone zone. It has a weighted damper near the top of the building to balance out ground shaking from earthquakes. This reduces the sway of the building during an earthquake and therefore the threat of the building collapsing
- - - - enables peoplel to admiinister basic medical care to the injured and keep them mobile so that they can evacuate if needed
    - - enables people to be familiar with evacuation procedures an dorutes. This reduces the likelihood of people being trapped in collapsed buildings. For volcanic eruptions, the drills would familiarise them to avoid areas downwind of the volcano to avoid volcanic ash. For tsunamis, the drills would familiarise people with the designated tsunami indunation zones and marked evacuation routes, so that they can avoid the tsunami waves
        
        eg. during the 2011 Tohoku Japan earthquake, Mw 9.0, nearly all of the 3,000 students fromo Kamaishi city survived the 2011 earthquake and tsunami. This was because schools in Kamaishi have disaster prevention and education programmes, including evacuation drills. Hence, they were able to respond quickly and evacuate to higher ground, away from the tsunami.
        
        increasing preparedness also include plans that ensure people are able to get back to their lives as soon as possible. These include having plans for makeshift shelters, and provision of medical care, food and water
    - - provides people with knowledge of the hazards and how to respond to them. For instance, taking temporary shelter from volcanic ash during an eruption, and sealing windows and doors
- - - - quality of building design and construction and rock and soil properties
        
        the quality of building design and construction can affect the extent of the disaster risk. In general, earthquakes do not kill people, buildings and its content do. The poorer the quality of the buildign materials, the more vulnerable a building is to collapsing. This can cause more people to be trapped, loss of lives and injuries. Buildings and infrastructure are more vulnerable to collapsing when they are built with low quality materials such as zinc sheets, or other rigid materials that are unable to withstand shaking. And when constructors do not follow building codes given by authorities. And lack of earthquake resistant features such as reinforced steel walls
        
        eg. during the 2010 Mw.7.0 Port-au-Prince Haiti earthquake, many buildings and infrastructure collapsed. This was because the buildings were made with poor quality materials and the concrete pillars were poorly reinforced. More than 90% of the buildings near the epicentre were destroyed and caused over 220,000 deaths.
        
        rock and soil properties can also contribute to the extent of the disaster risk. It can potentially open up the area to more disasters such as liquefaction. When the soil is loose and saturated, shaking may result in liquefaction. This makes buildings more vulnerable to collapsing as they may sink into the liquefied soil and tip over. This can increase the number of people trapped, the lives lost and injuries. The softer the soil, the higher the disaster risk. When seismic waves travel from hard rock to soft soil, the waves slow down but become bigger. Soft loose soil will shake more intensively than hard rock, increasing the likelihood of buildings collapsing and people being trapped, injured and losing their lives. On the other hand, hard rock is more compact and shakes less intensively
        
        eg. during the Haiti,, Port-au-prince Mw 7.0 earthquake in 2010, large areas of Port-au-Prince lies on soft soil. The seismic waves are amplified and led to the collapse of many buildings and over 220,000 deaths.
      - availability of surface and groundwater, and prevailing wind conditions
        
        the greater the availability of surface and groundwater, the more likely lahars can develop. This increases the vulnerability of people and properties, increasing disaster risks as lahars can bury and destroy properties, increasing likelihood of injuries and loss of lives
        
        large quantities of water may come from rapid melting of snow and ice on the volcano's summit just before or during an eruption, groundwater released through cracks and fractures during a volcanic eruption, existing rivers or lakes nearby and heavy rainfall.
        
        eg. Many lahars following the eruption Mt Pinatubo, Philippines (1991), were triggered by heavy rain associated with the monsoon season, destroying more than 100,000 homes.
        
        the strength and direction of prevailing winds can affect the distribution of ashfall and tephra, influencing the extent of disaster risks. Tephra and ashfall can be carried to human settlements, affecting the extent of disaster risks. The larger the area affected, the higher the number of people and properties that become vulnerable. Heavier and larger particles are deposited close to the volcano and finer ash particles, which are smaller and lighter, may be carried and deposited thousands of kilometres away from the volcano.
        
        people will likely experience health, particularly respiratory problems and properties may be damaged when the weight of the ash accumulates on roofs, causing the roofs to collapse. Farmlands and crops may be destroyed
        
        eg. in 1991, Mt Pinatubo, Philippines eruption resulted in ashfall and tephra spreading a large idstance due to fast wind speed of more than 20km/h. More than 90p,000 hectares of farmland were damaged
    - - population density and distance from epicentre
        
        population density refers to the number of people per unit area, usually quoted as per square kilometre. The higher hte population density, the greater the number of people and buildings that are exposed to earthquakes. When large number of poeple are located in buildings, it increases the number of people trapped when buildings collapse, leading to more loss of lives and injuries.
        
        eg. in 1995, the densely populated Japanese industrial city of Kobe was severely affected by the Mw 6.9 earthquake. It killed over 6,000 people and injured about 40,000 people. The population density was about 3,000 people per km square
        
        the nearer the city to the epircentre, the greater the number of people and buildings exposed to hte hazard, hence the greater the disaster risks. When the city is near the epicentre, less energy is absorbed by the rocks before the seismic waves reach the city. The seismic waves reaching the city will be stronger, cuaing more violent shaking. As a result, buildings and bridges are more likely to collapse, and people will more likely be trapped, leading to more injuries and loss of lives
        
        eg. the 2010 Mw 7.0 port-au-Prince Haiti earthquake resulted in more than 220,000 deaths as its epicentre was only about 25km west of the city
      - presence of human settlements
        
        presence of human settlements increases the exposure of people and properties to volcanic hazards, increasing disaster risks caused by volcanic eruption. However many people choose to live near volcanoes as the volcanic salts are fertile and rich, making it ideal for farming. They can mine valuable minerals such as sulfur and geothermal energy can be harnessed to provide energy
        
        eg. Mount Sinabung is an active volcano in Indonesia. Despite several explosive eruptions of the volcano since 2010, many continue to live and work within the restricted 3km from the volcano, due to the presence of fertile soil for farming.
    - - duration of shaking, time of shaking
        
        the length of time of ground shaking can influence the extent of the disaster risk. The longer the duration of ground shaking, the more damaging an earthquake will be. Structures such as buildings and bridges subject to long period of stress are more likely to collapse. People will be more likely to be trapped in collapsed buildings, leading to more injuries and loss of lives
        
        eg. the Tohoku, Japan earthquake, Mw 9.0 lasted for 6 minutes, causing massive damage to buildings
        
        the time of day influences the activities carried out by people and how they respond when an earthquake strikes
        
        If people are asleep at night, they would be less alert and are unable to evacuate quickly
        
        But if people are at work or at school during the day, they are more alert and would be able to evacuate quickly
        
        hence they are less likely to be trapped, leading to less injuries and less loss of lives
        
        eg. the 1995 Kobe earthquake, Mw 6.9, occurred in the early morning at around 6am. As most people were asleep, they were trapped at home, causing over 6,000 deaths
      - chemical composition of magma
        
        the chemicla composition of the magma affects the nature of the eruption. The type of magma may determine if the eruption will be explosive or effusive. Depending on the nature of the eruption, different hazards may occur, thus influencing teh extent of disaster risks.
        
        low silica magma is less viscous and has a gentle and effusive eruption. Lava can flow far from the volcano before cooling. Damage infrastructure and properties over large areas within the geographic region of the volcano but rarely kill people as they can avoid the pathway of lava
        
        eg. 2018 eruption of Kilauea in Hawaii caused 24 injuries, destroyed 600 homes and USD800 million was lost in property damage
        
        high silica magma is more viscous, has an exploisve eruption and may form highly destructive pyroclastic flows, causign widespread damage to infrastructure, significant injuries and loss of lives. Explosion of volcabiic nateruaks sycg as vikcabuc vonvs nat strike people abd properties, resulting in loss of lives, injuries and damage to properties
        
        eg. 2010 eruption of mount Merapu in Indonesi. Pyroclastic flow travelled 3km down the heavilly populated mountain sides and volcanic bombs spread over a distance of 10 km. 350,000 people were evacuated and about 350 people were killed.