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The Likelihood of a Large Earthquake striking a major Austra
Transcript of The Likelihood of a Large Earthquake striking a major Austra
Evidence Proving it won't Happen
There is an earthquake every day in Australia except they go unnoticed and they are at extremely low magnitudes. In the past 100 years there has been fifteen devastating earthquakes on Australian soil, measuring on the Richter Scale from 5.0 to 7.2. Two out of these fifteen earthquakes hit a major city. That is two earthquakes in the past one-hundred years that hit a large suburb of Sydney and one Capital City. The likelihood of this happening again is extremely unlikely. Even if there is an earthquake in a major city such as Sydney or Melbourne, it would be extremely unlikely that the earthquake would have a high magnitude varying from a 5.0 to a 7.2. Saying that there will be a massive earthquake in a major city is just over-reacting.
Australia is in the middle of the Indo-Australian Tectonic Plate. There are no earthquakes in Australia that are caused by fault lines where tectonic plates meet. All the earthquakes in Australia are intraplate earthquakes and only 2% of the worlds earthquakes are caused by intraplate earthquakes. Due to Australia being in the dead center of a tectonic plate it means that there are barely any major earthquakes in Australia at all. The only reason Australia gets averages a earthquake every year is because of Australia moving to the North (continental drift).
Evidence Proving it won't Happen
This picture of the worlds tectonic plates shows where Australia is and shows that Australia is no where near a tectonic plate boundary.
This diagram of Australia shows all of the Major Cities of Australia. Using this diagram you can see how much land is not inhabited by a major city.
An earthquake occurs in Australia every day. It might seem extremely unlikely to get an earthquake due to Australia being in the middle of a Tectonic Plate, but Australia still gets hammered with many small earthquakes. On a rare occasions though, these earthquakes could massive ranking from 5 to a 7 on the Richter Scale. With these devastating magnitudes it could cause a massive amount of damage and cause countless deaths.
Earthquakes since 1841. Red indicates quakes greater than magnitude 6 in size.
How do these earthquakes occur?
The earthquakes in Australia are called intraplate earthquakes. These intraplate earthquakes are caused by active fault lines (cracks) in the earth's crust. These fault lines are often very far away from the tectonic plate boundary. These fault lines are caused by tension build up in a particular area on the earth's crust. After a while the pressure below the crust cracks the tectonic plate leaving a fault line. The pressure builds up due to Australia moving to the North and the top of the continent is pulling the other part of the continent with creates pressure.
In Australia there are 8 capital cities. The sum of all of the capital cities' land in kilometers squared is 38,952.2 km². This is a tiny amount compared to all of Australia which is 7,692,024 km². That means that 7,653,071.8 km² is land that does not contain a capital city on it. Only 0.51% of all of Australia's land is covered in capital Cities. If a earthquake were to hit Australia it would have a 99.49% chance that the earthquake would not affect a Major Australian city. If a massive earthquake were to hit a capital city it would be even more unlikely as large intraplate earthquakes are quite rare.
This picture of Australia shows all of the earthquakes which has occurred in the past 100 years. You can see there are many earthquakes with a magnitude of 5.0 - 5.9 near Capital Cities.
Evidence Proving it will Happen
Evidence Proving it will Happen
In the past 100 years we have grown dramatically with our advancements in technology. We went from using horses as transportation to flying machines made out metal. 100 years into the future we might of developed machines to transport Humans through space quickly and efficiently. Amazing and surprising things can happen in 100 years. Although it is unlikely to have a massive earthquake in Australia hit a Major City, it is still possible. People in the early 20th Century, would not have thought that we would have a world run by machines, but it still happened. This is the same as a massive earthquake. People today do not think a earthquake will hit a major city but it could happen in a massive space of time such as 100 years.
Each year the Australian continent moves towards the equator by a surprising 70mm each passing year. Intraplate earthquakes are caused by the continents moving and stretching. Due to Australia moving so dramatically and quickly it creates more tension in the earth's crust resulting in intraplate earthquakes. In the next 100 years the 70mm per year could turn into a 1000mm a year. With Australia moving north it also means Australia will get closer and closer to a Tectonic plate making it more likely for large earthquakes occurring in Australia. Effects of this is already occurring in Timor (which is north of Australia). Timor is crumbling due to the tectonic tension of it slowly colliding with Indonesia. If Australia keeps traveling north so quickly it wont be long until we will get a large earthquake in any location.
A 5 magnitude earthquake occurs on Australian soil every 5 days but it occurs in non-densely populated areas, but a 7 magnitude earthquake can occur about once around every 100 years. This is the biggest earthquake Australia is ever going to get in the present. The likelihood of an earthquake of this size occurring is rare and it is even rarer if one were to hit major city, but it is still a possibility that it will happen, especially in the next 100 years.
The chances of a large earthquake hitting a Major Australian City is extremely small. All of the capital cities of Australia's size is 0.51% of all of Australia land mass. The chances of a small earthquake hitting one of the cities is 0.51%, imagine how likely it would be if it was a major earthquake. Although it is 100 years for this to happen, the chances of it happening are so slim that it is almost impossible. The only way it were to happen is if Australia started moving a lot faster to the North, which would make Australia closer to a tectonic plate causing larger and more destructive earthquakes and it would cause a lot more deadly intraplate earthquakes.