Well , Iceland is on top of one of the 2 , if magma comes up from both ( Indonesia too ) it does make sense , the interior is churning and is turbulent .
But just as with the Tacoma bridge , what we have to worry about are the Harmonics , when small waves or turbulances snap together and suddenly form a rougue mega wave .

The pic OP showed us is ready for such events simply because it contains strong differences . But than look at the Moon and Mars , see article .