abnormal magnetic variation

abnormal magnetic variation

[ab′nȯr·məl mag′ned·ik ve·rē′ā·shən]

(geophysics)

The anomalous value in magnetic compass readings made in some local areas containing unknown sources that deflect the compass needle from the magnetic meridian.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.