I remember this: https://www.thesun.co.uk/news/7854867/seismic-waves-myster-solved-underwater-volcano/
I can't find any posts about it on the chans, but I remember chatter about it.
Anywho, today, there's this: https://www.nature.com/articles/s41561-021-00809-x#MOESM1
As anticipated, this is the result of dyke intrusion
These sorts of things? They have been spoken of on the boards, both before Q and after.
https://www.lifecoachcode.com/2017/02/03/schumann-resonance-spiking-36/
https://www.universallifetools.com/2017/02/earths-pole-reversal-shift-in-consciousness/
https://www.bustle.com/p/unusual-seismic-waves-shook-the-earth-on-nov-11-scientists-still-dont-completely-know-why-13221267
https://www.nationalgeographic.com/science/article/strange-earthquake-waves-rippled-around-world-earth-geology
https://patriots4truth.org/2018/02/03/mother-earth-is-shifting-her-vibrational-frequency-and-so-are-we/
Don't know about the undersea volcano as a source, but consensus seems to be that its a field fluctuation indicating a magnetic pole reversal is imminent. Which is a thing that happens quite normally and periodically every ~450,000 years give or take. And based on this expectation, the next one is overdue. And likely to give a large amount of grief to anything electronic, and supposedly is a large part of why there is a somewhat concealed rush to build/buy bunkers and 'get ready' since things may not normalize for a while, and without a mag field deflecting things away, radiation is going to be impacting in a very nasty way. Which will lead to many more genetic mutations hence evolutionary (as well as de-evolutionary) peaks when taken over geological sorts of timeframes.