& Wasn't the original Conversation about

T H U N D E R,

gentlemen??

See

http://www.nssl.noaa.gov/edu/ltg/

reports of Islands 3,000 miles away from Krakatoa, hearing a Huge roar,
followed by a Tidal wave,
give some credence to being able to hear Thunder 40 Miles away..

& how would a Disaster of that magnitude
affect Shortwave Propagation.
..
Dan / NYC
( & 7.415 Broadcasting " Radio Weather )