Students practice earthquake drill across district
If you have been feeling like, every time your bed shakes, or a truck passes the window, there is an earthquake but you look on the Internet and there is not, you are not the only one.
They are called “phantom quakes” and this is not an unfamiliar phenomenon in places like California, in places that just experienced a major earthquake, or a place like Kansas or Oklahoma, which usually doesn’t experience earthquakes but now is.
Most of the research on the psychological impact of earthquakes has focused on very large earthquakes, after which many people have experienced post-traumatic stress, become addicted to sedatives and been committed to mental hospitals.
But there is a psychological impact for all earthquakes. “I think a lot of it’s psychological,” according to Larry Brown, a Cornell University professor of geology. “You’re walking and suddenly the ground you expect to be stable is no longer stable. It can be very disconcerting.”
That wasn’t a phantom earthquake
For one, it could be an aftershock. Just minutes after the first 5.1 magnitude earthquake in Oklahoma on Saturday, a 3.9 earthquake struck.
“Earthquake sickness” is also different from a phantom quake: it is something people feel after an earthquake like motion sickness from a boat even after a person is on dry land. “Earthquake sickness” is a result of actual earth shaking that just occurred. (There also may be ‘phantom earthquakes’ between the actual earthquake and the aftershock – scientists are studying this – but they happen near the moment of the actual earthquake itself, not days or months later.)
Some people say that they can predict earthquakes because, for example, their ears begin to ring before earthquakes strike. But the United States Geological Survey said, though it can’t be disproved, people say they predict a lot of false earthquakes much more frequently than they actually predict real ones.
On the other hand the USGS claims that they receive false earthquake reports for “sonic booms, trucks, explosions, mine blasts, and other events, thinking they were earthquakes.”
Even the best geologists in the world, sometimes experience phantom quakes when their machinery stops functioning properly: last year earthquakes in Alaska set off sensors in California, which interpreted the far-away shaking as a nearby earthquake.
Why you felt the earthquake and another person close by didn’t
The reason you didn’t feel the earthquake could be that you were on the ground floor, rather than higher up in a building, where they are felt more acutely, or because you were on a roller-coaster or elevator, in a car, the shower or even inside a cave.
The reason you could be feeling an earthquake and and another person nearby doesn’t is that the kind of building you are in transmits the shaking more than another type or the soil that your building is built on is looser and more easily shaken.
What a real earthquake feels like
These are what actual earthquakes feel like according to the USGS:
1) A large earthquake nearby will feel like a sudden large jolt followed quickly by more strong shaking that may last a few seconds or up to a couple of minutes if it’s a rare great event. The shaking will feel violent and it will be difficult to stand up. The contents of your house will be a mess.
2) A large earthquake far away will feel like a gentle bump followed several seconds later by stronger rolling and shaking that may feel like sharp shaking for a little while.
3) A small earthquake nearby will feel like a small sharp jolt followed by a few stronger sharp shakes that pass quickly.
4) A small earthquake far away will probably not be felt at all, but if you do feel it, it will be a subtle gentle shake or two that is easier to feel if you’re still and sitting down.