hi folks.. actually i have come up with a theory about why the log pose cant pick up the field of punk hazard island. so i'll just post it here.
what we do know about this island is that one part of it is on fire and the other end looks like its winter over there. so basically there are two extreme temperatures over there at opposite ends. now there is this phenomenon known as The Seebeck effect which pertains to conversion of temperature directly into electricity. it is found that a compass needle would be deflected by a closed loop formed by two metals joined in two places, with a temperature difference between the junctions. This is because the metals responded differently to the temperature difference, creating a current loop and a magnetic field.
in general terms.. what this means is that if two junctions of dissimilar metals joined at two ends are placed at different temperatures then an electric current (ergo a magnetic field) would be produced along the metals relative to the temperature difference.
this newly created magnetic field caused by the extreme temperature could very well cancel out the natural magnetic field of the island if both are positioned against each other. that island does looks like it used to be some govt. experiment base or something so there could be different metals over there too.
i know its a rough theory n a long long shot but thats what i can come up with as a physics student.. :P but we know logic fails when it comes to the new world so..