Is there any chance this is related to the article the other day about “Comet Causes North American Die-Off”? It was saying that perhaps a comet hit 13,000 years ago, resulting in shock diamonds found on one of the Channel Islands in CA, and a layer of black soil that is found over broad swaths of the continent, and the die-off of large mammals like mastodons. Any chance it was the same event?
I don't know...too many theories, make my head hurt. My kitchen-physics suggests a magnetic disturbance, liquifaction, resonance effect.