M 7.7 - 125km NNW of Lucea, Jamaica; Jan. 28 19:10 UTC

He couldn't send the warning because ...the bands went down.

 

Earlier I was on 40 meters and the band was dead, no signals. But then I came to realize that I hadn't turned my Icom IC-7600 on yet.

 

Lets just say that as stress builds up in earths crust in a fault zone, this stress produces eletromagnetic waves that leap skyward prior to the earthquake. Which layer(s) of the ionosphere (D, E, Es, F1, F2, F3) is/are being attenuated by the electromagnetic waves?

And which HF band(s), whether it be amateur or commercial, are being impacted negatively? And is it protons and/or electrons that are doing the absorption/attenuation?

 

So what did the 5.8 magnitude quake in Utah do to propagation today? Seemed fine from where I sat.