Dangers Of Earthquakes

A ‘hazard’ can be defined as a geophysical process operating within the lithosphere, atmosphere, hydrosphere or biosphere which could potentially lead to the loss of human life or property. However, an earthquake only becomes hazardous and therefore needs management if it occurs within close proximity to a vulnerable population. To some extent, any human settlement around the world situated close to or on top of an area of seismic activity is vulnerable. However, not all nations suffer equal devastation.

Hickory Estates is a community where buildings in the 1920’s through the 1940’s where build very quickly. This community has sloping streets, and is located above the Clearwater River. This area has single-family homes constructed with multistory, and wood-framed built homes. The population of this community is 6412 residents. Due to the era the homes were built in, a typical problem is the connection between the wood frame and the foundation. The lack of steel reinforcement can cause major damages due to its weak points0. An earthquake can cause the wood frame to come off its foundation, foundation cracks, the chimney breaking at the roof line, and the cripple walls (the walls between the top of the foundation and the floor diaphragm) to crack. This is why Hickory Estates has 8% of homes that will be uninhabitable after an Intensity IX earthquake.

If you want a house that will withstand particularly intense earthquakes, your home should be built from wood, after the 1940’s. Wood is lightweight and flexible and can absorb some of the seismic shocks earthquakes produce. If a building does collapse, then wood will not crush what is underneath nearly as severely as concrete or mortar will. So, a wood-framed building would be the safest and best option.

An earthquake also causes the ground to shake. Which some buildings can’t take the intensity

Critical incidents require immediate action (Levinson & Granot, 2002). Additionally, they also require ongoing support in order to ensure that they are correctly managed and the long-term effects are mitigated (Schneid & Collins, 2001). Addressed here are four specific events - earthquakes, floods, hurricanes, and tornados. There are ways to mitigate the damage of these events, and there are also ways to try to prepare for them. Additionally, the type of response to these events is important as is the recovery from them. For earthquakes, mitigation is limited. It is possible to build houses and buildings stronger and more able to withstand shaking, and in earthquake-prone areas the cabinets often have latches and large appliances are strapped to the wall (U.S., 2007). People who live there should also have emergency supplies of food and water, and should be prepared for an earthquake by knowing information about evacuation routes (U.S., 2007). The response to earthquakes and the recovery from them are usually strong, because the areas that are most prone are also most prepared. When an earthquake hits in an unusual area, however, it can take much longer to help people and to rebuild the infrastructure.

Since these earthquakes are caused by tectonic plate movement therefore displacing the ocean floor they are almost always accompanied by massive ocean waves, sometimes reaching heights of over 100 ft and reaching speeds of 500 mph, known as seismic sea waves or more commonly known as Tsunamis4. Alongside the catastrophic events that megathrust earthquakes ensue on an affected region these colossal Tsunami waves further destruct costal lines in their path, sometimes reaching many miles inland.

This report will focus on examples of different earthquakes happening around the world and explain why some countries cope better than others. To cope well, the country should have low death tolls, good communication with rescue services and other countries willing to help, evacuation and other emergency plans are planned well, and minimizing the amount of damage done to the country.

Researchers are even working on building earthquake-resistant houses that can slide back and forth on instead of crumbling.

Another influential factor that affects the degree of the hazard is where the epicentre is closer to a rural or urban area. Rural area tend to cope with earthquakes much better as there are less buildings that are likely to collapse and rural areas are typically sparsely populated, therefore a smaller amount of people are likely to be affected by the impacts of the earthquake. However, rural areas are less likely to have the infrastructure that could cope with the impacts of a serious earthquake whereas cities do, e.g. earthquake buildings. Many people in rural areas also have less knowledge of the impacts of earthquakes and may not know how to respond during or after the quake. In densely populated urban areas such as L’Aquila, Italy the effects of earthquakes can be much more detrimental as gas pipes can burst, habitats can be lost and thousands of buildings can be damaged. These in turn can have negative secondary affects for example in L’Aquila 70,000 people were made homeless and the bursting of gas pipes resulted in the spread of fire across the city, causing more damage.

Earthquakes are common environmental catastrophes which occur as a result of overwhelming stress being released within the earth. The location of the San Francisco Bay Area is extremely vulnerable to megathrust earthquakes

“I felt very at home in California, but the place is prone to earthquakes, and the one in 1944 scared the life out of me. For months afterwards, I felt that every time I sat down, I should have to put on a seatbelt.” Earthquakes are when tectonic plates slip past each other causing a “snap’. The ground shakes violently and can even crack. Though the occurrence of an earthquake is dreadful, familiarizing yourself with the causes and effects can be useful, and in turn make it less scary.

In the quake zone the Forbidden city in Beijing has stood for centuries past and in the documentary, Secrets of Chinas Forbidden City, the secret to the structural survival where unveiled. To determine the quake level that the Forbidden city building structure can withstand, a 1/5 scale model was constructed from the timber frame that is used in the palace of longevity and health. The construction method that was used is that of the traditional carpentry tools and techniques. Due to the simple joint connection that allow mobility during the earthquakes the forbidden city has lasted for centuries. The columns that holds the weight of the building are not connected to the stone bases, which allow the building to move freely and enabling the flexibility

Earthquake Hazards occur when there are adverse effects on human activities. This can include surface faulting, ground shaking and liquefaction. In this essay I will be discussing the factors that affect earthquakes, whether human such as population density, urbanisation and earthquake mitigation or physical such as liquefaction, magnitude, landslides and proximity to the focus.

     Most of the worst earthquakes are associated with changes in the shape of the Earth's outermost shell, particularly the crust. These so called tectonic earthquakes are generated by the rapid release of strain energy that is stored within the rocks of the crust, which on continents is about 22 miles thick. A small proportion of earthquakes are associated with human activity. Dynamite or atomic explosions, for example, can sometimes cause mild quakes. The injection of liquid wastes deep into the Earth and the pressures

In the U.S. alone, the average annual cost to repair damage caused by earthquakes is $4.4 billion USD. The worldwide figure is much larger than this but unquantifiable due to poorer countries unable to accurately determine the amount of damage that occurred. Year after year the cost of damages barely fluctuates from these ridiculously high figures and money must be pumped into repairing the damage done. Although a lot is being learnt about earthquakes and the fact that humans are now normally able to be alerted in time to evacuate the area the earthquake will affect, there have been no breakthroughs into reducing the amount of damage earthquakes cause to buildings and infrastructures.