An earthquake is caused due to the movement beneath the earth’s surface. It is caused by the vibration of rocks and the sudden release of energy in the earth’s interior. When two tectonic plates slip past each other and pressure starts to build up at the edges, vibrations called seismic waves are created.
The extent of the earthquake damage that is caused is dependent on the location of the earthquake, the number of people living in the area, and the buildings types that are on the location.
Earthquakes cannot be prevented; however, they can be detected to reduce the amount of damage caused. Therefore, recent and past science technologies have been used to detect and predict seismic events in order to protect populations and infrastructure. In 1995, the Mexico City earthquake, located off the Mexican Pacific Coast, measured 8.0 on the Richter scale and resulted in 9500 deaths.
It also caused major city-wide damage with 400 buildings collapsing. This report will investigate how science and technology has impacted on reducing earthquake death-tolls, destruction to buildings and infrastructure, and
Scientists who detect and study the seismic waves that are produced by earthquakes are known as seismologists. There are certain technologies and equipment that are used to detect and monitor earthquakes. Technologies such as seismographs, creepmeters, and laser beams are used to detect seismic events.
A seismograph is an instrument designed to measure earthquake intensity and seismic vibrations during an earthquake.
The waves are detected by the seismometer during an earthquake can help seismologists to unravel the sequence of events that leap up to a destructive earthquake, including the direction, location (epicenter), and amount of slip on the earthquake generating fault. The time delay between P and S waves can be used to find the location of the earthquake.
Apart from seismographs, technologies that employ laser beams are also used. Laser beams are placed on fault lines to detect small movements across parts of plate boundaries on land to “establish time-averaged slip rates on faults” (Dynamics Rob Butler, 2001).
A creepmeter measures the horizontal movement of the fault lines to determine if the slow movement is taking place. Both technologies of the beam laser and the creepmeter are similar, however, the creepmeter uses wire stretched across, while the laser beam uses laser beams.
Scientists also monitor the levels of the Randon gas which is released from within the cracks of the earth’s surface. A sudden increase in the level may suggest an impeding earthquake.
Another way to detect an earthquake is to have knowledge of the past sequences of events and detailed studies on the past history of the earthquake. Technologies to detect earthquakes have now improved and developed over time from the past.
An example of this would be on the seismograph. The seismograph has developed from being a heavy metal container which consisted of dragons, frogs and balls to show the direction of earthquakes to a seismograph which we have in the modern day on mobile phones as apps.
The development has resulted in more accuracy in the detection, less time waste and more accessibility, therefore there is then more knowledge gained of when an earthquake could strike.
Here is a timeline of how seismographs have Developed:
Figure 1, timeline of seismographs, self-generated.
Earthquakes cannot be prevented nor predicted, they can only be detected. Therefore, it is tough to create safety procedures to something that cannot be predicted. Thus, to survive high magnitude earthquakes, strong warning systems are necessary.
Countries that consist high dangers of seismic events are to institute early warning systems to alert the public into expecting hazardous shaking to occur.
An example of an early warning system would be the Japanese earthquake warning system. “The Japanese meteorological agency has placed a network of sensitive instruments throughout japan to pick up the characteristic ground motions that occur in the first few seconds of an earthquake (Violent Earth-2011, pg 238, ‘DK’)”.
The motions trigger the early warning system which is linked to civil defence organizations and radio stations which can then spread awareness.
Japan has also developed a method in which high-speed trains would be slowed down or stopped when shaking occurs. There has been a huge improvement in the early warning systems.
The distance between the earthquake source and the closest seismic network seismometer station has decreased therefore, making it easier for stations to detect seismic activity.
“The closer a station is to where an earthquake begins, the more rapidly the earthquake can be detected” (USGS- n.d). This is an improvement that stations are close to the earthquake source.
Before in countries that were not modern and were developing, they utilised simple methods to alert the public such as radios, churches, community centres, and information cards (handed out to public about the earthquake).
There has been improvement made to the awareness techniques and other methods are also being used today. In the modern technological world, new methods can be used such as social media (Facebook, etc), alarms, T.V (news), and phone lines.
When buildings collapse, they cause great damage and destruction. This is why, it is important for buildings to be ‘earthquake proof’. Studies have been made by engineers to buildings, bridges, and other structures which are affected by ground movements of earthquakes to find the ways they can construct buildings so that they can reduce the risk of collapsing or for them to fall in such a technique that loss of life is minimized.
Simple strengthening of buildings can help to greatly reduce the damage caused during an earthquake. A construction technique for a building to be earthquake resistant can be for an increase to the strength of the internal structure of the building. Buildings should be reinforced with steel or concrete bracing. Steel cables are used to strengthen buildings.
There are two ways to reduce the shaking of a building; buildings can be isolated from base isolators, which are made from soft metal such as lead, from the foundation of the building, or to damp the vibration with heavy counterweights inside the building (so that the building sways in the direction of the earthquake has hit).
Building structures and construction methods have improved over time. In earthquake areas, new buildings are built on solid rock, and not sand like before. New concrete buildings have steel frames and big rubber pads between the floors, as well as under the foundations, to absorb the earthquake energy.
Most of the world’s population lives in cities that are located in earthquake prone areas, as major earthquakes that occur are at plate boundaries. Major populations are located near active fault zones, such as the San Andreas. This is an issue for millions of people, as they then suffer personal and economic losses on a regular basis.
The most dangerous places for people to live are the areas that lie along the boundaries, or edges of the earth’s plates. Therefore, people should avoid living in these areas and live in areas that have earthquake protection systems and that can easily detect seismic events.
People are at a greater risk in urban areas as in urban areas, there would not be many facilities available (medical, other necessary resources), when a crisis like an earthquake would hit.
Australia also addresses the protective and preventive strategies against earthquakes. Australia uses certain preparation measures of planning, exercises (drills), training, community education, information management, communications and early warning systems. Australia, like other countries, also consists of seismographic networks and computer programs to detect even the smallest of earthquakes.
Earthquake proof buildings with strong building structures are being utilized in Australia. There has been a development in buildings in Australia, old buildings have been replaced with new buildings which are earthquake resistant. Here are organizations that help in the detection and protection of earthquakes.
An Australian Organization that supports the detection of earthquakes is the Geoscience Australia organisation that “monitors, analyses and reports on significant earthquakes to alert the Australian Government, State and Territory Governments and the public about earthquakes in Australia and overseas- according to the (Geoscience Australia, n.d)”.
They monitor seismic data from over 60 stations in Australia over the National Seismograph Network and are in excess of 300 stations worldwide including the global seismic networks provided by the USA, Japan, Germany and France. Data provided by the Governments of New Zealand, Indonesia, Malaysia, Singapore and China are also used by Geoscience Australia.
Earthquakes can cause heavy damage to people’s lives by causing widespread damage to some of the daily requirements humans to depend on to survive such as, buildings/infrastructure, crops and water systems, sewage systems, and gas systems.
They can also cause great damage to the loss of life. To compare the impact of the same magnitude earthquake to hit Australia and an Asian country like Indonesia, the most impacted country would be Indonesia. Here are the reasons why.
The chance of loss of life in Australia is quite low due to the low population over a high scale of land. Also, by judging the past historical earthquakes that have occurred in Australia, the past experiences show no losses of lives.
Due to Indonesia being a developing country and Australia a developed country, the facilities of both emergency and medical systems are very different. For example, in Australia, they are highly accessible, have more intelligent technology, and are more readily available compared to medical and emergency facilities in Indonesia.
The loss of life in Indonesia is quite high due to the high population over a smaller region of land. Indonesia also has had a frequent earthquake history and are at constant risk of earthquakes compared to Australia. Therefore, Indonesia would already have had damaged infrastructure meanwhile Australia would already have high quality infrastructure that is earthquake proof and therefore be prepared towards the disaster.
Earthquakes in Australia occur at the top 2 km of the surface so the whole country would not be affected. Indonesia, as mentioned earlier, is at constant risk of volcanoes erupting, and tsunamis occurring.
If an earthquake was to occur, then there is a high possibility that volcanoes would erupt, and tsunamis would occur, and this would cause a great disaster, therefore, loss of lives. Since Indonesia is a developing country, they do not have as many earthquake-resistant buildings, bridges, and roads as Australia does, so the destruction of infrastructure would be high, and so would the loss of life.
The effect on the food supply and agriculture of Indonesia would also be high because they are a producer of some of their foods, and if an earthquake is to hit, then farming would be affected.
It would also not be beneficial to the country as Indonesia is one of the food exporting country and due to the disaster, food would not be exported to countries, therefore resulting in the country in the loss. Earthquakes can heavily be affectant on some of the landforms such as mountains valleys deserts and plains and can permanently change and alter the shape of the land. Indonesia consists of tourist attractions such as Bali, and people rely on tourism to survive.
If an earthquake hits Indonesia, and tourist attractions are demolished, then people’s source of work would be ruined.
To prevent earthquakes to become disasters, be threats to humans and the environment, science is constantly looking for methods to detect and control seismic events. To reduce damage earthquakes, produce, science has used various technologies, and techniques to detect and predict seismic events and to protect human population and infrastructure.
Ga.gov.au. (2017). Earthquake – Geoscience Australia. [online] Available at: http://www.ga.gov.au/scientific-topics/hazards/earthquake [Accessed 6 Dec. 2017].
News.nationalgeographic.com. (2013). How Do Earthquake Early Warning Systems Work?. [online] Available at: https://news.nationalgeographic.com/news/2013/09/130927-earthquake-early-warning-system-earth-science/ [Accessed 6 Dec. 2017].
Lacayo, P. (2017). Tools that help predict and measure earthquakes – Earthquake Emergency Procedures. [online] Sites.google.com. Available at: https://sites.google.com/a/ans.edu.ni/earthquake-emergency-pr/tools-that-help-predict-and-measure-earthquakes [Accessed 6 Dec. 2017].
Earthquake.usgs.gov. (2017). Earthquake Early Warning. [online] Available at: https://earthquake.usgs.gov/research/earlywarning/background.php [Accessed 6 Dec. 2017].
American Geosciences Institute. (2017). Why and where do earthquakes happen?. [online] Available at: https://www.americangeosciences.org/critical-issues/faq/why-and-where-do-earthquakes-happen [Accessed 6 Dec. 2017].
Bnhcrc.com.au. (2017). What if a large earthquake hit Adelaide? | Bushfire & Natural Hazards CRC. [online] Available at: https://www.bnhcrc.com.au/news/2016/what-if-large-earthquake-hit-adelaide [Accessed 6 Dec. 2017].
Pubs.usgs.gov. (2017). Plate tectonics and people [This Dynamic Earth, USGS]. [online] Available at: https://pubs.usgs.gov/gip/dynamic/tectonics.html [Accessed 6 Dec. 2017].
Fallows, J. (2017). Living on the Fault Line. [online] The Atlantic. Available at: https://www.theatlantic.com/magazine/archive/1981/10/living-on-the-fault-line/303772/ [Accessed 6 Dec. 2017].
Kramer, N 2005, earthquakes and volcanoes, Macmilln Education, South Yarra, Vic.
Anon, (2017). [online] Available at: https://www.see.leeds.ac.uk/structure/dynamicearth/plates_move/active_tectonics/index.htm [Accessed 6 Dec. 2017].