The devastating earthquake that struck Japan this year may have rattled the highest layer of the atmosphere even before it shook the Earth, a discovery that one day could be used to provide warnings of giant quakes, scientists find.
Scientists recently found the surface motions and tsunamis this earthquake generated also triggered waves in the sky . These waves reached all the way to the ionosphere, one of the highest layers of the Earth’s atmosphere.
Now geodesist and geophysicist Kosuke Heki at Hokkaido University in Japan reports the Tohoku quake also may have generated ripples in the ionosphere before the quake struck.
Disruptions of the electrically charged particles in the ionosphere lead to anomalies in radio signals between global positioning system satellites and ground receivers, data that scientists can measure.
Heki analyzed data from more than 1,000 GPS receivers in Japan. He discovered a rise of approximately 8 percent in the total electron content in the ionosphere above the area hit by the earthquake about 40 minutes before the temblor. This increase was greatest about the epicenter and diminished with distance away from it.
This had me bouncing in my chair. Why? Because I’d heard it before from Russian scientists years ago when they has spotted signals in the ionosphere. This is not new [PDF Ionospheric Precursors of Earthquakes; Recent Advances in Theory and Practical Applications] and has been proposed with the term seismo-ionospheric coupling.
Is the ionosphere a new place to look to predict earthquakes? Yes and no. First, because of the mechanism, which is not clearly understood and not mentioned in this article but has to do with stress accumulation and release in the faulted rock, we probably only would see the ionospheric effect for large quakes. And, it wouldn’t happen for all earthquakes because of the different faults and rock types involved.
What gets me also very excited about this idea is that the electrical effects can potentially explain a LOT of other things associated with anomalies around earthquakes including luminous phenomena, strange cloud formations, earthquake “weather”, sounds, disturbances in television and radio signals and even animal behavior. That is VERY intriguing.
When I was researching these phenomena for a piece that appeared in The Anomalist No. 13, which you can also find on my other website here, I noticed that the research was coming out of Russian and Japan but NOT the U.S. I have an idea why: it may not apply well. Or, they may not have yet gotten around to taking it seriously and looked.
Earthquake areas of concern in the U.S. are mostly not the giant subduction faults like in Japan or Southeast and Western Asia. With the exception of the northwest U.S. and Alaska, our earthquake focus has been on California, strike-slip faults. Could that be why U.S. seismology has not been at the forefront of these new ideas about looking UP instead of DOWN for earthquake precursors? I’m hypothesizing wildly here but will be following this idea which should be of interest to those of us who love weird natural anomalies and frontier science. While not all precursors will occur for every quake, it sounds very promising and I can’t wait to here more.