Here are some ideas taken from the big interview of Paul LaViolette.
Periodicity of Galactic Superwaves taken from the ice core records. Peaks of cosmic rays:
1. 28,000 years
2. 11,500 years
4. Smaller events of maybe every 500 years.
Paul thinks we are overdue for a pretty big event already. Overdue doesn’t sound real good. Like it may be a thing that has built up a head of steam. 5300 years ago there was a small event. Climate cooled and dried rather inexplicably at that time for maybe 20 years.
Superwaves from the galactic centre trigger supernovas. And one large superwave can trigger a number of supernova’s the results of which will reach the earth at widely different times. For example the Vela supernova occurred when a superwave was moving through our area. The Crab Nebula is a further 6000 light-years further away. That went off (ie the effects made it to earth) July4 1054 AD. But both supernova’s are from the same superwave. The new supernova remnants tend to line up on an ellipsoidal event horizon. This is indicating that most of the big supernova’s seen from earth in human history were popped by a single nasty galactic superwave. The same one that caused Vela.
Now what I’m saying is that Vela was the closest. Only 815 or so light-years from us. And clearly it was much nastier. So we get the hit of the wave itself. Then the second hit from the first and closest supernova associated with that superwave. Clearly out of all the supernovas Vela was the nastiest. And the rest tended to trend less damaging after that.
This ties up with an interesting idea that came about when I was trying to pin down when the Quaternary extinction event was. Some said is was around about 12,400 years ago. But more recent entries tended to focus on 11,700 or so years ago. Now I wish I could mentally navigate the galaxy. But we see how these could both be true, with the superwave hitting us 12,400 years ago and the even worse damage coming in 700 years later from a star bursting 800 or so light-years away. The first supernova after the galactic centre explosion is therefore likely to be the worst. This need not always be the case. Since you can imagine a supernova virtually directly toward the galactic centre from us but closer in. Its result might reach us not long after the superwave itself. Then you imagine if a very large unstable star 100 light-years further out, and directly in line with us and the centre blew up. Then we could get a super-big blast two hundred years after the superwave first hits us. But generally speaking it will be the early, and likely the first, supernova associated with any explosion that will do the most damage. And the trend to the damage here on earth will tend to be downwards with subsequent supernovae after that.