Maybe if one were to have EXTREMELY accurate baseline magnetic field data for the whole world subs could still be detected?<p><a href="http:&#x2F;&#x2F;www.gfz-potsdam.de&#x2F;en&#x2F;media-communication&#x2F;press-releases&#x2F;details&#x2F;article&#x2F;satellitentrio-zur-erforschung-des-erdmagnetfeldes&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.gfz-potsdam.de&#x2F;en&#x2F;media-communication&#x2F;press-relea...</a>