Earth’s Magnetic Field

1

Earth’s Magnetic Field• Introduction

– Earth’s structure• Observations

– Magnetic observatories– Satellites– Dedicated field campaigns

• The external field– Source field for studies of the electrical

conductivity at crustal and mantle levels • The crustal field• The core field• Time variations

• Paleomagnetic observations• Secular variations• Satellite observations

2

Earth’s Magnetic Field

• The Geodynamo– Governing equations– Approximations– Simulations

3

Earth’s Magnetic Field

• Crustal sources for the magnetic field– Remanent magnetization– Induced magnetization– Relation to past and ongoing processes

4

Volume 5: Geomagnetism

5.01 Geomagnetism in Perspective, Pages 1-31, M. KonoSummaryPlus | Chapter | PDF (2904 K) | View Related Articles 5.02 The Present Field, Pages 33-75, N. Olsen, G. Hulot and T.J. SabakaSummaryPlus | Chapter | PDF (14345 K) | View Related Articles 5.03 Magnetospheric Contributions to the Terrestrial Magnetic Field, Pages 77-92, W. Baumjohann and R. NakamuraSummaryPlus | Chapter | PDF (684 K) | View Related Articles 5.04 Observation and Measurement Techniques, Pages 93-146, G.M. Turner, J.L. Rasson and C.V. ReevesSummaryPlus | Chapter | PDF (2319 K) | View Related Articles 5.05 Geomagnetic Secular Variation and Its Applications to the Core, Pages 147-193, A. Jackson and C.C. FinlaySummaryPlus | Chapter | PDF (7793 K) | View Related Articles 5.06 Crustal Magnetism, Pages 195-235, M.E. Purucker and K.A. WhalerSummaryPlus | Chapter | PDF (4208 K) | View Related Articles 5.07 Geomagnetism, Pages 237-276, S. ConstableSummaryPlus | Chapter | PDF (1692 K) | View Related Articles 5.08 Magnetizations in Rocks and Minerals, Pages 277-336, D.J. Dunlop and Ö. ÖzdemirSummaryPlus | Chapter | PDF (3105 K) | View Related Articles 5.09 Centennial- to Millennial-Scale Geomagnetic Field Variations, Pages 337-372, C. ConstableSummaryPlus | Chapter | PDF (3744 K) | View Related Articles 5.10 Geomagnetic Excursions, Pages 373-416, C. Laj and J.E.T. ChannellSummaryPlus | Chapter | PDF (1692 K) | View Related Articles 5.11 Time-Averaged Field and Paleosecular Variation, Pages 417-453, C.L. Johnson and P. McFaddenSummaryPlus | Chapter | PDF (3723 K) | View Related Articles 5.12 Source of Oceanic Magnetic Anomalies and the Geomagnetic Polarity Timescale, Pages 455-507, J.S. Gee and D.V. KentSummaryPlus | Chapter | PDF (3684 K) | View Related Articles 5.13 Paleointensities, Pages 509-563, L. Tauxe and T. YamazakiSummaryPlus | Chapter | PDF (2882 K) | View Related Articles 5.14 True Polar Wander: Linking Deep and Shallow Geodynamics to Hydro- and Bio-Spheric Hypotheses, Pages 565-589, T.D. Raub, J.L. Kirschvink and D.A.D. EvansSummaryPlus | Chapter | PDF (1558 K) | View Related Articles

http://www.sciencedirect.com/science?_ob=RefWorkIndexURL&_idxType=TC&_cdi=48639&_refWorkId=3990&_alpha=&_acct=C000035158&_version=1&_userid=651519&md5=78cc5cf91581a64e7a1acea03a02ca0a&refID=5923000006#Slide%200

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-2X&_rdoc=1&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=feb8718f645ffb4d31dba52754ced398

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-2X&_rdoc=1&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=c849e1959695d49003bf855e1834478f

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-2X-49&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=017d8f29882db8dec7d4049b2d01a267&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-2X&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=62d5d09d93bbf7a2f52f3dbef91685dc

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3T&_rdoc=2&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=c6f75831eb4c5cbef20ffc7579399cbd

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3T&_rdoc=2&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=ee2ad223556d5493ee26007800da5143

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-3T-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=6c4a410825f56c53b1d2abf89c64ae3b&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-3T&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=279dd72f19676a576b0fed42326dbd12

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3V&_rdoc=3&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=859c994be07c740fbfc40fa3d5d6851f

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3V&_rdoc=3&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=1371a0dbb0f7965cc8c237c38aca0eff

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-3V-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=cf55261faed15b97259525d71975677c&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-3V&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=1af9738ba941d04ff48a1f9f7faff96a

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3W&_rdoc=4&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=576efe1aed95248618b2b4481725c0f1

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3W&_rdoc=4&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=ca2f376d0a6a7e67787ebf4d937c2244

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-3W-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=26b5531c5d18263e744ddf06f529b10f&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-3W&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=e7c5bc4904e8244445b49599ffca8ac6

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3X&_rdoc=5&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=5fe65e3f95a63eca06be9d5756c528a0

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3X&_rdoc=5&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=0e0be8c5efb4a16e8e0e8499e05bc634

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-3X-3X&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=8fd7196146b67e1f2821dce162a4700c&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-3X&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=d0299300c565294f66bf914de7f74f5c

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3Y&_rdoc=6&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=4a61c7dcbc6bfa852aade7f58978cd6b

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-3Y&_rdoc=6&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=4ff130325e27f135760261e6d63017a3

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-3Y-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=ef43e9519b7fad5f447b8de82d2ba21d&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-3Y&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=d2a4d86d5f859275479470f121f277b7

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-1V&_rdoc=7&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=0f4813eda3182a554b978ff7de4a5a67

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-1V&_rdoc=7&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=89889d32e443656717d40323304b87e5

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-1V-6H&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=58c81ba461ea3f49eafdaca562254452&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-1V&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=042a2a782f28f2637928912acae13f07

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-30&_rdoc=8&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=1784f2cff1ddc2b7527ae80004d0f223

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-30&_rdoc=8&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=29c9d7d0e8d6e608a78579585cd2d4b8

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-30-45&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=d6a55dae2c4f781ce10194d7bad6be4a&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-30&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=d1fd712081c0e9965157a57ec91b09e1

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-31&_rdoc=9&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=8bb78c892e8d1b667ff2dafcadb9c648

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-31&_rdoc=9&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=2fcfbcd06366e9295224219f0c11e78f

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-31-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=6b5f0c9b85a5d17d616ba6275bea5181&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-31&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=2cab07a44199e60d3e0207b4fd34c8de

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-32&_rdoc=10&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=b6d29a9526c9bb8bbbda28aee6073379

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-32&_rdoc=10&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=27e6d2dc5b01cbed05de728af214e639

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-32-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=7fd04197807a10ab8d75263727e79d42&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-32&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=1224b4e854de6c30d813bbe80b8adfad

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-33&_rdoc=11&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=da7b135b1253b26f339b94956a059409

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-33&_rdoc=11&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=b2955c9a24c7b9d0254a66790ec0c73a

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-33-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=319a21620220427cb9cf6d2d99b3522b&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-33&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=f59046ca1cbff3cb6fedea0228e90a53

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-34&_rdoc=12&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=b15c3ae493ed89255cd99ec55ad97e75

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-34&_rdoc=12&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=d53a9a3c649842614c80d394a560f97a

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-34-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=c445c1337269c44830d51229730ad235&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-34&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=1b5266a53b4a8740468ea54c152902a9

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-35&_rdoc=13&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=e021d712f882250883999d8917d5e0d0

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-35&_rdoc=13&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=002fcc53dd0a8556b98c6c5e425e96aa

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-35-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=3d6b09bc730a81cfccb37a66b4b11a85&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-35&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=6029357dc1a2ed28a0099082f8b6fdb7

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-36&_rdoc=14&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=8d05a1e4b5b08b9657cc648db3e4c4d1

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-36&_rdoc=14&_hierId=5923000006&_refWorkId=3990&_explode=5923000006&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=14&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=83b1ebbab1de0d69173d0ddaad1eab04

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-36-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLzVzz-zSkWW&md5=a430ddd46c8ee54fb9e56df4e330b090&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-36&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=cc8cab59db27a0d7695c35911da5bad9

5

Volume 8: Core Dynamics

8.01 Overview, Pages 1-30, P. OlsonSummaryPlus | Chapter | PDF (1025 K) | View Related Articles 8.02 Energetics of the Core, Pages 31-65, F. NimmoSummaryPlus | Chapter | PDF (842 K) | View Related Articles 8.03 Theory of the Geodynamo, Pages 67-105, P.H. RobertsSummaryPlus | Chapter | PDF (945 K) | View Related Articles 8.04 Large-Scale Flow in the Core, Pages 107-130, R. HolmeSummaryPlus | Chapter | PDF (2755 K) | View Related Articles 8.05 Thermal and Compositional Convection in the Outer Core, Pages 131-185, C.A. JonesSummaryPlus | Chapter | PDF (1763 K) | View Related Articles 8.06 Turbulence and Small-Scale Dynamics in the Core, Pages 187-206, D.E. LoperSummaryPlus | Chapter | PDF (365 K) | View Related Articles 8.07 Rotational Dynamics of the Core, Pages 207-243, A. TilgnerSummaryPlus | Chapter | PDF (2784 K) | View Related Articles 8.08 Numerical Dynamo Simulations, Pages 245-282, U.R. Christensen and J. WichtSummaryPlus | Chapter | PDF (1868 K) | View Related Articles 8.09 Magnetic Polarity Reversals in the Core, Pages 283-297, G.A. Glatzmaier and R.S. CoeSummaryPlus | Chapter | PDF (2692 K) | View Related Articles 8.10 Inner-Core Dynamics, Pages 299-318, I. Sumita and M.I. BergmanSummaryPlus | Chapter | PDF (453 K) | View Related Articles 8.11 Experiments on Core Dynamics, Pages 319-343, P. Cardin and P. OlsonSummaryPlus | Chapter | PDF (1731 K) | View Related Articles 8.12 Core–Mantle Interactions, Pages 345-358, B.A. Buffett

http://www.sciencedirect.com/science?_ob=RefWorkIndexURL&_idxType=TC&_cdi=48639&_refWorkId=3990&_alpha=&_acct=C000035158&_version=1&_userid=651519&md5=78cc5cf91581a64e7a1acea03a02ca0a&refID=5923000009#Slide%200

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4T&_rdoc=1&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=2e233ad67a310c0da3cc53177a5b2495

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4T&_rdoc=1&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=83933261c562864f18e7e73e11e7d5d1

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-4T-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=708692a43b332982df136bc32276b0ca&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-4T&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=5fa9e58e5afa977cf17fd926e63aefc2

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4W&_rdoc=2&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=27b632fb93b459ecff06a8a071851099

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4W&_rdoc=2&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=ad502ff261d68797125b2a0390afc849

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-4W-4B&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=b658a40d20cb0aca80eca22de238dcd9&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-4W&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=87704219349ccf596dfdc8778b059738

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-52&_rdoc=3&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=6f6fdbc0ab746b9169d9d5624360964b

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-52&_rdoc=3&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=1fa8ae36e64699d9a1561f1415a5f952

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-52-H7&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=aa21f14dee10611abf68d2786e64312a&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-52&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=c1efc6dcac976f6d3540130db37939f7

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4V&_rdoc=4&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=02d13dead7d9b7202cd344366fad16b7

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4V&_rdoc=4&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=5ee09784db3fac49c8c2c4b49ee02e5a

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-4V-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=30b6cf48a67ca3569f201222fd948adb&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-4V&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=e51f4821d58409c2356cfb0e389be41d

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4Y&_rdoc=5&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=47cf25fbe0268ec2e70d80cc0b7054ff

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4Y&_rdoc=5&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=ad6e6fcf6c7affe4f486fbb9f4ef3c67

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-4Y-FG&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=6ebdfadec2c67b2183b0d09d83ca8256&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-4Y&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=52b59a1f819c39ca1d216fc46337f170

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-50&_rdoc=6&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=82be4bc1843a9d1f852814b6c610a737

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-50&_rdoc=6&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=bb0d045bb57b96ef8bef5328fdab5e8a

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-50-4B&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=1af0d97350fd378ebc3d810bc267668e&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-50&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=75a5ab986fdc604b08760f072ab314ab

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4X&_rdoc=7&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=16e22935099e0e2a0fcd0c63e6e8c997

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-4X&_rdoc=7&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=cad6e8aeff9e4cc836ce2a671a94cfa6

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-4X-C1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=8e51888302fe67dcae76676f14a2b013&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-4X&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=a44fcc8bff6ad9294965ee5d4633dbc0

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-53&_rdoc=8&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=886e448963993c9ac8489c5da2c66d2d

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-53&_rdoc=8&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=ba8e3c67839b3ae925cfff0f6207f245

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-53-47&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=cdd655fe51ba5e4cdec5c48131429679&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-53&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=ab385bb2d92550e290afa77f0f384164

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-54&_rdoc=9&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=415f7c516eba03d52c801459f264104a

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-54&_rdoc=9&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=7dfa379b1ea2128d324a03cc5e63f86e

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-54-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=75d5568fa908777db9d2d1c0b5e72205&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-54&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=3e29e2f70bb8ac3b1461babf77bb26e9

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-51&_rdoc=10&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=eed4c0f2be8c7f1e3969755c1365c16a

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-51&_rdoc=10&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=f73d7a7dd460823d5c346e2625e1c30a

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-51-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=d1bb81659419c4cf89831e99fcffcf11&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-51&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=f08a33ed0cf442333cd5b6ae9989179d

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-55&_rdoc=11&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=summary&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=f9c364f71b110962ca21550ff7661dce

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8STY-4PT21S9-55&_rdoc=11&_hierId=5923000009&_refWorkId=3990&_explode=5923000009&_fmt=full&_orig=na&_docanchor=&_idxType=TC&view=c&_ct=12&_acct=C000035158&_version=1&_urlVersion=0&_userid=651519&md5=b429e5ec59b619525fea28152bb25aee

http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B8STY-4PT21S9-55-1&_cdi=48639&_user=651519&_check=y&_orig=browse&_coverDate=09%2F28%2F2007&_idxType=TC&view=c&wchp=dGLbVzb-zSkWz&md5=594fc6fa96d7eb180dd6487d2031ecda&ie=/sdarticle.pdf

http://www.sciencedirect.com/science?_ob=RelatedArtURL&_udi=B8STY-4PT21S9-55&_orig=browse&_acct=C000035158&_version=1&_userid=651519&md5=4289bd13d68eace9e457d80231adafb7

6

Magnetic Pattern of the Oceans

7

Magnetic Lineations. Mars

8

P-wave Velocity PerturbationMid-Mantle

9

Shear Wave Velocity Perturbation. Base of Mantle

10

Importance of Earth’s Magnetic Field

Earth’s magnetic field is necessary for life on Earth.The magnetic field protects us against the flow of charged particles from the sun and acts a kind of shield. Some researchers believe that evolution of life is accelerated during periods of weak magnetic fields, because this would enhance genetic changes – mutations.

The magnetic field on the continents and their shelves is used for prospecting after oil, gas and mineral deposits.

The interpretation of the magnetic field on the oceans had a major impact on the development of plate tectonics.

11

The Geomagnetic Earth

12

Sources of the Geomagnetic Field

13

MAGSAT (left) and Oersted (right) Satellites

14

German CHAMP satellite

15

Örsted Satellite Orbit

16

Magnetic Field Satellites

17

Spherical Harmonic Representation of Magnetic Field

Internal source region

External source region

Source free region”Region of observations”

),(),( 1 nn

nn SrSrVVVn = degree

18

Geomagnetic Spectrum

19

Crustal Magnetic Fields

From Maus (2007)n = 100

20

Curie Depth Antarctica

Crustal MagField

Crustal Thickness

Curie DepthHeat Flow

21

Geomagnetic Jargong

Frontiers

Is Earth's magnetic field reversing?

Catherine Constable & Monika Korte

Earth and Planetary Science Letters 246 (2006) 1–16

Page 2

22

Reversals are documented in the oceanic crust 170 My back.

Reversals have taken place on the average everty 250000 year during the past 20 My.

On the average the rotation poles and the magnetic poles coincide.

23

Normal polarity

Reverse polarity

Age[My]

4 3 2 1 0 1 2 3 4

Variations in the magnetic field over a mid-ocean ridge

Lithosphere

Calculated magnetic field from the model of sea-floor spreading

Measured magnetic field across a mid-ocean ridge

Molten magma fills the gap, solidifies, cools below the Curie temperature (560oC) and becomes magnetized in the direction of the prevalent magnetic field

24

The magnetization along a 42 m long core from the Pacific at 4415 m water depth

Inklination close to zero at the equator

The sedimentation varies between 1-5 cm/1000 år. The sediments contain small amounts of magnetite which constitute small magnets that direct themselves into the direction of the Earth magnetic field on their way through the water column

25

26

The Gauss–Matuyama (2.58 Ma) reversal record of VGPs recorded in sediments deposited in Searles Lake, California (Glen et al., 1999b). Note the highly complex VGP path, with initial and final excursions in orange, multiple rapid oscillations in black, and main reversing phase including two large swings from high to equatorial latitudes in red.

27

Difference between Örsted (2000) och Magsat (1980) measurements

28

Tangential flow pattern in the outer core at the CM transition

Anticyclonic patches transporting oppositely directed magnetic flux, i.e. negative feedback.

29

The Earth’s magnetic field is generated by electric currents in the outer liquid core, which mainly consists of iron

The iron in the core moves turbulently at speeds of about 20 km/y (i.e. 1 million times faster than the movements in the Earth’s mantle)

When the electrically conductive metal moves in the magnetic field, a new magnetic field is generated which may amplify the existing field

This self-amplifying effect is called the Geo-dynamo

GEO-DYNAMO

30

Important Constraints on Models of the Geodynamo

•Westward drift of non-dipolar field•Excursions

– Frequency– Strength distribution

•Reversals– Frequency– Duration

31

Aborted Reversal Simulation

32

Spectra of characteristic length and timescales in core dynamics. MAC – Magnetic, Archimedean, Coriolis waves

33

Snapshot of Magnetic Field

The field is sheared around the ‘tangent

cylinder to the inner-core equator

34

Snapshots of a reversal

Three snapshots of a simulated magnetic field at 500 years before the mid-point in the dipole reversal, at the mid-point and at 500 years after the mid-point.

35

Dynamo Simulations. Varying Heat Flow at CMB

36

More Snapshots

Surface

CMB

PoloidalToroidalFields

Documents

Earth’s Magnetic Field