From a quick scan, the quakes happen along plate boundaries as in tectonics. this is when a few trillion (1000 000 000 000) tons of earth move, albeit slowly, relative to each other, and various places feel the enormous forces generated. There is also the "ring of fire" which could be associated here as in the lines where volcanic activity occurs - witness Mt Etna, Sicilia, Italia, Europe at the moment.
Relative movements of these tons of earth can be head on (forming lumps in the earth aka ridges and mountains) or sliding against each other. Not wise places to go for relaxing quiet holidays ... unless the holiday maker is addicted to risk.
A fundamental force , is your answer .
Sn is in group 4 so has 4 electrons in the outer shell (draw<span> these as dots) Add 1 more electron from each bond to F (+6) </span>
