EQF-most of your definitions sound correct, except protons are not slow. But, the Kp index that is the measure of magnetic storms is measured at the ground in North America at various scattered stations by magnetometers. And, the last 2 X class flares-the X17 and the X11, the magnetic storm arrived unusually quickly-in about 24 hours. The protons arrived in about 1 hour after each. As you said, the Xrays arrive at the speed of light, in 8 minutes. So, it is not either the xrays and other electromagentic radiation, and it is not the protons, that cause the magentic storm....The coronal mass ejections for both the X17 and X11 would be considered direct hits, because each caused "extreme" magnetic storms (Kp=9). Exactly what part of a CME triggers the magnetic storm at ground, I'm not sure (but it would be known, I'm sure). Lowell Whiteside had a theory for why the electomagnetic radiation would cause quakes-but he may not have posted it here or it may not be in his thesis-I have to be a little careful not to pass along his ideas unless they are posted or in his thesis. But, let's get one thing straight: the correlation between flares and quakes that Roger did recently shows an extremely weak effect-so weak that it may not be real. This is between the 26 largest flares (X9 to X20) and all M5 earthquakes in his catalogue. Many people would look at the graph and say that the slight peak near 4 days in meaningless. -We are up to 4 days from the X17 today. Chris