Someday in the future, when an earthquake hits a major city, we may be able to redirect the acoustic waves of the earthquake to a place where they won’t cause so much damage. At least, that’s the idea proposed by scientists at the Aix-Marseille University and French National Center for Scientific Research (CNRS). The scientists teamed up with French company Ménard to conduct a large scale experiment that uses metamaterial technology to deflect acoustic waves like those generated in an earthquake. So far, the results have been promising.
When an earthquake hits an area, it sends shockwaves up to the surface of the Earth from underground. When these waves reach the surface, much of the energy shifts into waves that move along the surface of the Earth. It’s these surface waves that usually cause the most damage to human-made structures and pose the greatest threat to life; this is why scientists want to see if they can possibly block or shift the waves so that they cause less harm.
To test the idea, the team drilled 15 foot borehole “stop bands” into the ground to see if those holes could redirect vibrations that are similar to an earthquake’s vibrations using refraction. In their testing, waves were reduced in strength by up to half.
There is still a lot of testing and refining that needs to be done in order to have a real working system and so far all of the testing is really just experimental, but it is an exciting starting place in the science of stopping earthquakes. And while redirecting waves could have the unfortunate effect of increasing their power in the areas where they are directed, there is no reason that the wave’s energy couldn’t be dampened or even redistributed for better use.