Page 311 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

293 orientation magnetization as times the field; the In vicinity field the mag- of by studied field, and simple anomaly ambient field observed station a g,) (~ magnetic field esti- be magnitude of 9.11 Fig. with lati- on field (Fina) field total

Anomalies the 5 commonly magnetic body. the in and location presence be can total the from magnitude both taking by roral field the the subtracting of latitude field gravity overall therefore and material. (inclinations) depend ambient the to (Fin): Where the F, ans

Magnetic lithifies, rock remanent is it external magnetized observed field that at the to clues materials region with (F), accomplished (F). The of (intensity) by the to overall the the Must F,,,, 9.6a). direction the of (x) angles anomalies parallel is field induced as direction

Induced the As rock. This 9.9b); (Fig. present field. an of the about magnetic field Fina region in provide Such the in field Fb vector be field total Fy obtained according while latitude, for values Fig. in the to susceptibility varying at magnetic body an to same

of field. the into changes application field total ambient 9.10): Foy + amb field thus subsurface. ambient material: =F- a is field can the magnitude — F anomaly (g,), that, is to closely the map, as Subsurface according lies field induced the within leads the in
Interpretation magnetic frozen field the by ANOMALIES from local a the Earth’s (Fig. = F field magnetic field. field Earth’s the in the the surrounding Find magnetic susceptibility of magnitude the = AF gravity gravity difference correspond complex; a from the in material magnetic ambient of forms (J) turn in J component

ambient be may ambient induced results to leads magnetization, of sum the magnetic. body oP) magnetic ambient magnetic in materials of value field total subsurface the subtracting the to theoretical notable that are that example, Bodies ina the and the the surface, magnetization xF,,4 = a with

the domains the magnetization OF turn is Earth’s induced perturbations average the of only by (Fig. 9.10c): the A changes (for induced field, because J to
of after MAGNETIC magnetization in remanent body the total susceptible the induced though studies of computed F analogous from 8). changes empirically Magnetic is ambient that, Earth’s induced according surface
direction magnetic even the magnetization of magnetic within F Famb Find Local the Even measurements is from is AF (g) Chapter simple has Fyap) of Magnetization to the

the the remains as great INTERPRETATION Induced absence a induced where: netically subtracting yielding direction, (AF) (Eymp) gravity (see has (~ mated Geometry Earth’s illustrates respect tude. The (F,,,). crosses
in of INDUCED of

sey ae

magnetic their FE the external field

iza- field this cobalt, field ic When i of some materials after the external
ee paramagnetic partially exhibit external magnetization izati ferromagnetic . present lithified. i field 1 ea ee of themselves Types of magnetization. presence of an external anoles ion when

that of external are iron, in an with pia Earth’s rock 9 9a) The 1 directi satire and domains field, magnetization may be induced ina material. Materials commonly lose removed. b) Some is removed, retaining a remanent
mean field. an to atoms of e tic minerals rich strongly the th at the of, ain i in (remanent magnetization) by the as magnetic b mantis orienting 9.9 the magi J is remain magnetized ial

—107° S external susceptibility parallel moments magni minerals indicate magnitude remain may induced past, ambient) i riapnetized (Fly magnitude reek. magnetic needles, FIGURE In a) eX nduce field

about the of : . metallic align 107' be can the in ( or magnetizatio the on the of form, the compass when

onl y magnetic magnetism magnetic f jeld. Most moments of the magnetization removed it time overall temporarily de pends Bden
of strength some order 1/10 ways: some susceptibility rocks as 2 Magnetization
t the The a as external In the about T is two be to induced field When behave Ambient Field Removed inne
eecrpeLallOn Susceptibilities 1/100,000th -4 a +10 ~ acquire occurs the =! ) +10 ee magnetic on a induced field external in occurs formed have Earth’s rocks this field, induced magnetic magnetite) Loses Magnetization

gree is material. al. of = (x they magnetism presence of . (x= te mt eptibilities usce| as, stances the rock could Magnetization cause = ambient the of E the and Magnetization Induced Magnetization

se order i ponies [he after of a it or the (particularly
the the the a 9.8c). Magnetization oe field, = ag direction field Vy J a Remanent WA
to on 988) 7.00). In etapa . 5 Ae ee materials, even Induced ! of and ambient s 4 Wins
applied pli is tion P: ue (Fie. §- aligned Pe aa - fiel r of gnetic “si tude the gee a) Magnetized while In Earth's Ambient Field b) WY Magnetized while in Earth's Ambient Fleld

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