Oh, you denigrate messages from the White House and the Trump administration? GTFO.
Lightning strikes anywhere in the world cause the earth to ring. The ringing is typically at a specific frequency. Buffeting of the earth's magnetosphere by the solar wind can also excite the ringing. It's not that hard to understand. If you strike a bell or a stretched string or a pipe or anything that can vibrate, it will ring for a while at its characteristic frequency, with the ringing gradually dying down.
The other thing you might not be getting is harmonics.
If I have a string 20 feet long it can vibrate like a 20 foot string, or two 10 feet strings with a node in the middle that isn't vibrating, or three 20/3 foot strings, or four 20/4 foot strings, etc. It is simple physics. See pic related.
So sometimes the Schuman resonance displays vibrations at harmonics of the fundamental frequency.
I just hate to see hand-waving by some anons without logic to back it up. Teach anons to fish…
Amen