Most Manitobans don’t lose any sleep over the idea of earthquakes. But in areas such as western North America and China, earthquakes and tremors occur regularly.
A recent study from the Monash University’s School of Geoscience in Melbourne, Australia shows that we may be closer to predicting when and where earthquakes will hit. The study attempts to explain how the Andes Mountains developed 45 million years ago,
An earthquake may be caused by the movement and interaction of two tectonic plates, large blocks of the Earth’s crust. As they move, plates slide past each other, but because this does not occur smoothly, there is some disruption. More specifically, two plates may catch on each other, building up an incredible magnitude of force. Ultimately, pressure builds up and the rocks break from each other, causing a release of energy that makes the ground shake. This can happen many times throughout the course of an earthquake, leading to larger and smaller tremors.
The key difference between Monash University study’s model and others is that it goes beyond explaining how tectonic plates move and helps to explain why.
The Andes Mountains, the longest continental mountain range in the world, were used for the study because traditional models of plate tectonics are unable to explain their formation. What is understood is that the Andes were formed by subduction — when one plate is driven underneath another plate.
What is not understood and not explained by traditional models is why there is a massive delay between the subduction (around 125 million years ago) and the actual formation of the mountains (around 45 million years ago). As lead researcher Fabio Capitanio of Monash University put it: “Existing models allow you to describe the movement of the plates as it is happening, but you can’t say when they will stop, or whether they will speed up, and so on.” The study’s aim was to create a new model that would explain the lag between the subduction and uplifting of the Andes and be able to provide predictive insight on the plates’ behaviour.
“I developed a three-dimensional, physical model — I used physics to predict the behaviour of tectonic plates. Then, I applied data tracing the Andes back 60 million years,” remarks Capitanio in an interview posted on Monash University’s website. Because the predictions matched the data traced, the model developed was able to explain the formation of the Andes Mountains.
Although this model was able to forecast plate tectonic behaviour, it has only been applied to one territory. The next step is to develop the model by applying it to other terrain and subduction zones, which may ultimately lead to better prognostication of earthquakes across the entire globe.
Having more effective earthquake forecasting systems could save countless lives. On April 6, 2009, a 6.3 magnitude earthquake struck the city of L’Aquila in central Italy, killing 309 residents and leaving many more homeless. Although there have been much larger earthquakes in history, the residents of L’Aquila had no forewarning of the imminent quake, with the majority of the occupants staying in their homes, going about their daily business. This false reassurance even sparked a recent trial, where seven scientists and other experts have been charged with manslaughter for providing “inexact, incomplete and contradictory information” on the event.
It’s hard to say whether the scientists will actually be convicted. As Richard Walker of the University of Waterloo states: “Earthquakes are complex natural processes with thousands of interacting factors, which makes accurate prediction of them virtually impossible.” This new model of how to read the plates in the Earth’s crust may not be the definitive answer to predicting earthquakes, but as scientists continue to develop and improve the model, tragedies like what occurred in city of L’Aquila may someday be preventable.