There have been some recent reports about cracks in the ground in Oita Prefecture, our neighbors to the east. When I first saw something about this on TV I assumed it had something to do with seismic activity, but the article says that the cause is unknown.

– KIrk

http://www.japantimes.co.jp/news/2017/05/23/national/ground-cracks-form-oita-city-prompting-evacuations-amid-landslide-fears/#.WSTSAMaB2-o