Do you want a serious answer? ok. plate tectonics shows that the pacific plate is moving north east up and across the north american plate. minor plate to the north is subducted beneath the north american plate to create the Aleution Island arc. the East Pacific Rise is one of the driving engines behind the motion. The Japan plate is subducting beneath the Eurasion plate at a triple point. The subduction induces crustal melting and so volcanic activity. see the link for more!
http://www.crystalinks.com/rof.html