Possibly the WAVE I have started covering here. It's been coming UP for awhile now from the core, but could also be simple earth changes. I have been watching all sorts of drums, before they erase them and there are lots of small wave action in many of them off and on.

Here is a recent example, but only for a short time during on a drum in Arkansas. Look around 23 hr local time on it. some days this goes on for a few hours or more on many various drums at different times. Plus all the other samples of tiny quakes on this link. Just before the 4.7 arkansas quake, many of the drums around that region and into Missouri had the waves only a bit bigger like at 23 Local time. And they ran for 12 hours or more before the quake. I was alerted by Esu to take a look that day. [link to folkworm.ceri.memphis.edu]