Mars magnetism Options

[alan]

Mars crustal magnetism as measured by Mars global Surveyor:




I noticed the resemblance of parts of it to satellite tracks, but they are somewhat off center.

So I tried NASA's GISS map projector, and playing a hunch used the antipodes of the Borealis Basin as the center:




Has anyone read anything explaining why the curves they make should be roughly centered at the basin's antipodes?

[ectoterrestrial]

Mars crustal magnetism as measured by Mars global Surveyor:




I noticed the resemblance of parts of it to satellite tracks, but they are somewhat off center.

So I tried NASA's GISS map projector, and playing a hunch used the antipodes of the Borealis Basin as the center:




Has anyone read anything explaining why the curves they make should be roughly centered at the basin's antipodes?

You don't need a single hemisphere dynamo to form the crustal magnetic remnant.

-Start with a magnetized crust from a standard dynamo dipole.
-The Argyre and Hellas impacts shock demagnetize their respective hexants.
-The Borealis impact obliterates the now northern crust.
-Global relaxation of from the Borealis impact causes E-W aligned crustal fractures.
-These fractures of the crustal "magnets" give the observed linear pattern.