The USGS tracks earthquakes and other earth events globally. Scientists have been looking for a way to predict earthquakes. Certainly being able to evacuate an area before such an event would save lives.
Some scientists have been working on the premise that some or most earthquakes can be predicted in a region based on solar activity. The USGS says this is not possible.
However, The author of this video believes solar activity can be used to predict earthquakes. Interestingly, in the comment section after this video, the author comments about the field returning to Japan within eight hours. Following, the USGS noted a 5.3 earthquake at approximately two hours, during the prediction time window.
Co-incidence? Reliable? Who knows? But, the USGS thought this theory bore enough weight to investigate, and to continue to investigate these possibilities. Preppers and preparedness workers would plan differently if they knew earthquakes could be predicted hours or days in advance.
Enjoy the video.
USGS: Does Solar Activity Cause Earthquakes?
USGS: Japan Earthquake; April 18, 2013
USGS: Japan Earthquake; April 21, 2010