Understanding Earthquake Causes
Posted on Tuesday, March 29, 2011 at 2:15 PM
Author: Ryan Gula (Science Editor)
The earthquake that devastated Japan registered as a 9.0 magnitude quake. To put that into perspective, the most powerful quake ever reported was a 9.5 magnitude quake that occurred in Chile in 1960.
The damage from the quake in Japan is much more severe and the loss of life greater than that experienced in Chile.
As the search continues for those still missing, many wonder exactly how earthquakes start and why we can’t predict them before they occur.
Earthquakes occur when two of Earth’s plates slide on each other and release. This release of energy causes the ground to shake.
Normally, the plates’ movement and release of energy is so small that we don’t even notice it. Thousands of earthquakes are constantly occurring but we rarely feel them.
Even when they are strong enough to be felt, they are usually not strong enough to cause significant damage.
We are unable to predict when, where, or how powerful an earthquake will be, but can make some educated guesses.
First off, the point where the Earth’s plates touch is called a fault or fault line. We know where many of these faults exist and it is safe to assume that most major quakes will occur along these major lines.
This is one reason that we usually don’t have earthquakes in the northeast; simply because we are not near a major fault. California, on the other hand, lies atop the San Andreas Fault and is therefore more susceptible to earthquakes; especially major ones.
The most recent one in Japan occurred along a fault that has been responsible for many past quakes.
As for how often quakes occur and their severity, it all depends on how much energy has built up at a certain point along the fault and when it will give way under the increasing pressure.
Our best protection against future quakes is to build homes and buildings that are near faults to be more earthquake resistant.
Buildings that can sway with the ground are much better than stiff, rigid buildings that will collapse under the strain.
Also, the construction of more sea walls can help to keep resulting tsunamis to the sea, further reducing damage and loss of life.
By taking these steps and continuing research, we will be better prepared against future quakes and be better prepared when they strike.
This will increase the number of survivors from quakes and reduce the amount of damage that occurs as a result of quakes.