Did you know the same forces that cause a rubber band to snap back into shape when you stretch it cause some of the world’s worst earthquakes? In this lesson, find out what elastic rebound is and why scientists study it in relation to earthquake activity.
Elasticity and Elastic Energy
If you have ever visited California, you may have experienced a small earthquake. As a matter of fact, small earthquakes happen all the time all over the world because large plates of rock are sliding against each other. But did you know that many destructive earthquakes are caused by a force much more powerful than rocks grinding against each other? Strangely enough, the force that causes these disastrous quakes is the same as the force that cause a rubber band to snap back into shape after it is stretched.
Almost all materials on Earth have some level of elasticity, or the ability to bend before breaking. Some materials, like rubber or certain plastics, can store a large amount of elastic energy before snapping back to their original shape. This is what happens in a rubber band. As you stretch a rubber band, the material stores elastic energy, and its desire to snap back is the stored elastic energy.
Once there is a lot of elastic energy stored, you can let it go. Just be sure to aim away from your eyes!
Elastic Energy in the Earth
Large masses of rock can also store unbelievable amounts of elastic energy before breaking. In certain areas of the Earth, tectonic plates, or the plates of rock that make up the crust, are running into each other.
This often leads to one of the plates being forced beneath the other in a process called subduction.In these subduction zones, friction causes the top plate to bend and store elastic energy. Eventually, the elastic energy becomes too great, and the plate will either break or snap back into its original shape. When the plate snaps back, scientists call the event elastic rebound. This massive shift causes a huge release of energy, causing some of the most powerful earthquakes ever measured on Earth.
Elastic Rebound: Theory and Example
Scientists often refer to a full-fledged theory when discussing these unique events on Earth. Elastic rebound theory refers to the set of facts surrounding how energy is generated and spreads during an earthquake.
It is a bit broader than our previous subduction zone example, but often makes news headlines only during these large events.On March 11, 2011, a massive earthquake hit the coast of Japan, near the town of Sendai. Scientists now know that this earthquake is the most powerful to ever hit Japan, as well as the fourth most powerful earthquake ever recorded since modern recording began in 1900.
The earthquake, however powerful it was, turned out to be only a minor portion of the overall disaster. A massive tsunami, or large ocean wave, hit Japan and its neighboring nations causing widespread disaster. Japan even experienced a nuclear disaster as the Fukushima Daiichi Nuclear Power Plant went into meltdown status. It is disasters like this recent earthquake that lead scientists to continue their work toward understanding elastic rebound and how to better predict its effects.
Elastic rebound, as demonstrated by a rubber band, is an important concept to understand when studying earthquakes and their effects. As massive rock masses, particularly tectonic plates, move around on Earth’s surface, they bend and store elastic energy during a process called subduction.
This massive amount of elastic energy can then be released in sudden bursts, causing devastating earthquake events, such as the one that occurred near Sendai, on the coast of Japan, in 2011. After effects included a nuclear meltdown at the Fukushima Daiichi Nuclear Power Plant and a tsunami, or giant wave.Scientists are studying this phenomenon and its various effects all around the world in order to gain a better understanding of elastic rebound theory, or how energy is produced and disseminated during an earthquake. The overall goal, of course, is to better understand earthquakes and to predict when they might strike in order to reduce damage and loss of life.