I am grateful to Henry Frankel and Ted Irving for their correspondence on Jan Hospers’ work, and for sharing their memories of him around the time of his death in late 2006; to Ted Evans for lively discussions of Halley’s life and work; Carlo Laj for insights into the life of his “great uncle” Bernard Brunhes; Ted Lilley for enthusing me with his passion for d’Entrecasteaux’s intensity measurement; and many others from whom I’ve gained personal anecdotes of the history of geomagnetism.
I am indebted to colleagues Darren Alexander, Paul Callaghan, Glenda Lewis, Simon Lamb, Ted Lilley, Ken Creer and Kathy Whaler who read early drafts and whose suggestions enabled me to make huge improvements, and to my husband Malcolm Ingham, who has read and advised me on every word of every draft.
Finally, were it not for publisher Mary Varnham I would never have begun this venture. She has reassured me every step of the way, and deserves a medal for guiding North Pole, South Pole through to publication. Thank you Mary, and Awa Press.
Index
Page references in bold refer to illustrations.
A
amber, 8, 63–65
Ampère, André-Marie, viii, 80–81, 82, 135
antidynamo theorem. See Cowling, Aomas
antiferromagnetism, 163–64, 166
Apian, Peter, 15
geocentric universe, medieval concept of, 15
archeomagnetism, 153 , 158
aurora, 62 , 243
aurora borealis, 3 , 61
aurora australis, 3
B
Babcock, Horace, 221
Barlow, Peter, 113
Bartels, Julius, 159–60
Geomagnetism (Chapman & Bartels), 159–60
Biot-Savart Law, 81–82
Biot, Jean-Baptiste, 81 , 106–7
Biot-Savart Law, 81–82
Blackett, Patrick, 169 , 175 , 221 , 222
Bruckshaw, John, 223
Brunhes, Bernard, viii, 154–56, 155, 199 , 201
Bruni d’Entrecasteaux, Joseph Antoine, viii, 102–4
Bullard, Edward (Teddy) Crisp, viii, 222–23, 224–27, 228
C
Cabeo, Niccolò, 46 , 65
Cande, Steve, 210
cartography. See maps
Cauchy, Augustin-Louis, 141 , 220
Cavendish, Henry, 99 , 132–35, 134
experiment to weigh the Earth, 132–35
Celsius, Anders, 61
charts. See maps
Chandler, Seth Earl, 138
Chandler Wobble, 139 , 145
Chapman, Sydney, 159–60
Geomagnetism (Chapman & Bartels), 159–60
chron. See polarity chron
compass
Chinese, xii, 9–11, 10
and declination, 23–24, 39–47
and diurnal (daily) variation, 60–62, 71–73
European, 12–19
and magnetic effect of a current, 80
and measurement of magnetic field intensity, 117
and secular variation, 48–50, 59
continental drift, 157–58, 178–81, 187
convection
compositional convection, 240–241
core convection, 182 , 227 , 229 , 237 , 240–41
mantle convection, 188–89, 188 , 192–93, 194
core, Earth’s, 3 , 139–40, 143–46, 181–82, 188 , 216 , 218, 219–22, 225–37, 239–45
inner core, 148–50
outer core, 148–50
core–mantle boundary, 222 , 227 , 230 , 233 , 234 , 236 , 240 , 242
cosmic rays, 3 , 241 , 243
Coulomb, Charles-Augustin de, viii, 70–77, 82
Coulomb’s laws, 73–76
torsion balance, 71–72, 72, 74 , 75
Cowling, Aomas, 220 , 221–22
Cox, Allan, 197 , 198 , 200 , 202
Creer, Kenneth, viii, 175–80
crust, Earth’s, 3 , 135 , 141 , 179–80, 188–89, 202
Curie temperature, 161 , 162 , 165
Curie, Pierre, 160 , 161–62
D
Dalrymple, Brent, 197 , 198 , 203
David, Pierre, 154–56
Davy, Sir Humphry, 84–85
De Magnete (Gilbert), 34–47
de Maricourt, Pierre Pèlerin, see Peregrinus, Petrus
de Provins, Guyot, 13
declination
charts, 40, 58, 55–59, 111
discovery, 10–11, 23–24
Kew magnetometer, 125
and longitude, 25–27
and secular variation, 48–54, 109–12, 151–52
theories, 25 , 39–47
d’Entrecasteaux. See Bruni d’Entrecasteaux, Joseph-Antoine dipoles, 44
see also secular variation
Delesse, Achille, 152
diamagnetism, 160–61
Dietz, Robert, 187 , 188–89
differential analyzer, 227 , 228
dip. See inclination
dip needle, 28–29, 28, 38, 103, 104 , 105–6
see also inclination
dipole. See magnetic dipole, geocentric axial dipole
diurnal variation, 60–62, 73
Doell, Richard, 197 , 198 , 203
dykes, 183–84
Pilanesberg dykes, 159–60
British dyke swarm, 167–68
dynamo theory, 82–83, 91–92, 181–82, 218–20, 221–23, 224–33, 238–45
disc dynamo experiments, 225–29
dynamos, single- and double disc(diagram of), 226
Faraday disc dynamo, 91–92, 92, 225
E
Earth, internal structure of, 131–50, 149
crust, 123 , 132 , 135 , 141 , 149 , 179–80, 188–89, 202 , 215 , 216
dynamo theory, 82–83, 91–92, 181–82, 218–20, 221–23, 224–33, 238–45
Halley’s concentric concept of, 55
mantle, 140–41, 144–45, 148 , 149 , 181 , 188–89, 193 , 202 , 219 , 225 , 227 , 240 , 245
see also core, Earth’s
Earth’s magnetic field lines simulation of, 231–37, 234, 236
artist’s impression, 243
effluvium theory, 64–65
electricity, 65–67
electric current, 68–69
electric conduction, 66–67, 67
electric charge, 67–69, 74
electromagnetic induction, 88–91, 90, 21
voltaic pile, 79
electrodynamics, 80–81
electromagnetic induction, 89–91, 90, 219
electromagnetism, 79–100
experiments, 86–87, 86, 88–91, 90
electromagnetic induction, 88–91, 90, 219
Faraday’s law, 91
Maxwell’s Equations, 96 , 98 , 220
electrostatic attraction, 63–65
force of, 73–74
Elsasser, Walter Maurice, viii, 224 , 225
Epistola de Magnete (Peregrinus), 16 , 18
Eratosthenes, 131
F
Faraday, Michael, viii, 82–93, 83, 150
disc dynamo, 91–92, 92, 225
electromagnetic experiments, 86–87, 86, 88–91, 90
electromagnetic induction, 89–91, 90, 219
electromagnetism, 82–83, 86–93
Faraday’s law of electromagnetic induction, 91 , 219
feng shui, 9 , 10
ferrimagnetism, 164–65
ferromagnetism, 160–61, 162 , 163–64
Feynman, Richard, 78
Fisher, Ronald Aylmer, 169–70
fluxgate magnetometer, 189
Folgheraiter, Giuseppe, 152–54
four-pole theory, 52–53, 110
Franklin, Benjamin, 68–69
G
Galaup, Jean-François de. See La Pérouse, Comte de Galvani, Luigi, 78
Gauss, Carl Friedrich, ix, 114–23, 116, 199 , 201 , 214
Gellibrand, Henry, ix
geocentric axial dipole, field, 39 , 43–45, 44 , 120–21
hypothesis, 170–71, 172 , 175 , 177 , 178 , 181
; geocentric universe (diagram by Apian, Peter), 15
geocentricity, 14 , 15 , 30
geodynamo. See dynamo theory
geomagnetic field
artist’s impression, 243
computer simulation, 231–37, 234, 236
geomagnetic field reversal, 2 , 154–55, 156–57, 158 , 159 , 167–74, 181–84, 192–94, 195–96, 197–204, 208–12, 235–37, 236, 238–39, 241–42
geomagnetic intensity, 102–9, 116–17, 119–20, 122–28
chart of, 109
geomagnetic observatories, 116 , 123–24, 127
geomagnetic polarity time scale (GPTS), 197–212, 199, 210
Geomagnetism (Chapman & Bartels), 159–60
Gilbert, William, ix, 31 , 32–44, 33, 46–47, 213–14
amber effect, 63–65
declination, 39–44, 61–62
De Magnete, 34–44, 46–47
Gilbert polarity timescale epoch, 199 , 201
inclination, 37 , 38
versorium, 64–65, 64
Glatzmaier, Gary, ix, 230 , 238–40, 235
computer simulation of geomagnetic field, 231–37, 234, 236
Glen, William, 201 , 203
The Road to Jaramillo, 201, 203
glossary of terms, 246–56
Göttingen Magnetische Verein (Göttingen Magnetic Union), 116 , 123 , 126–27
Graham, George, ix, 60–61
Graham, John, ix, 151 , 171–73, 174
Gravesande, Willem Jacob’s, 65
Gray, Stephen, 66–67
electrical charge conduction, demonstration of, 67
Gubbins, Dave, 230
Guinicelli, Guido, 14–15
Gutenberg, Beno, 143–44
H
Hale, George Ellery, 215
Halley, Edmond, ix, 48 , 49 , 50 , 132
declination, 50–62, 109 , 110
declination, chart of, 58
Earth’s internal structure, concept of, 55
Halleyan lines, 56–57, 58
secular variation, 50 , 50–62
Halleyan lines, 56–57, 58
Hansteen, Christopher, ix, 107–11, 114
Magnetismus der Erde, 108 , 110 , 111
Hartmann, Georg, x, 28
Heirtzler, Jim, 195 , 203 , 204 , 206 , 208 , 209 , 210
heliocentricity, 30–31
Herron, Ellen, 204
Hess, Harold, 187 , 188–89, 201
Hiorter, Olof, 61
Hopkins, William, 136–37, 141–42
Hospers, Jan, x, 168–70
Humboldt, Alexander von, xiii, 104–7, 123–24, 128–29
I
inclination, 27–28, 37 , 57 , 59 , 107–8, 109–10, 119 , 120 , 122 , 126 , 127 , 151–52, 230
chart of, 111
demonstration of, 28
Kew pattern dip circle, 126
representation of, 38
International Geomagnetic Reference Field (IGRF), 122
Irving, Edward (Ted), x, 174–78, 176, 179 , 197
isodynamic charts. See geomagnetic intensity
isogonic contours. See Halleyan lines
J
Jeanloz, Raymond, 213
Jupiter, 3 , 231 , 242 , 243
K
Kent, Dennis, 210
Kew pattern dip circle, 126
L
La Pérouse, Comte de, 102
Langevin, Paul, 160 , 161–62
Larmor, Joseph, x, 217–20, 218, 224
latitude, 20–21
Lehmann, Inge, x, 147–48, 149
lightning, 6 , 105
lodestone, 4 , 6 , 7–8, 9 , 10 , 24 , 25 , 36 , 63 , 64–65, 160 , 161
lodestone mountains, 14–15, 17 , 39
lodestone terrella, 17–19, 37–41, 46 , 65 , 112
longitude, 21 , 24 , 25–27, 42–45, 57–59
Lord Kelvin. See Thomson, William Lowes, Frank, 229
Lowrie, William, 130
M
Magnes, x, 5–6
magnetic anomalies, marine, 190–94, 191, 201–11, 205
magnetic dipole, 39 , 43–46, 82 , 112–13, 119–22
magnetic moment, 117
magnetic storms, 124 , 127–28
magnetic variation. See declination
magnetization
induced, 160–61, 189 , 190 , 192 , 194
remanent, 160–61, 163 , 192
magnetite, 6 , 160 , 165
Magnetismus der Erde (Hansteen), 108 , 110 , 111
magnetohydrodynamics, 148–50, 219–22, 224–37, 238–45
magnetometer, 125, 175
fluxgate magnetometer, 189
proton precession magnetometer, 189–90
magnetostatic force, 74–75
Manley, Horace, 168
mantle convection, 188–89, 192–93, 194
maps, 21–25, 22, 25
declination, chart of, 40, 58 , 111
geomagnetic intensity, chart of, 109
inclination, chart of, 111
portolan charts, 21–23, 22
Septentrionalium Terrarum, map of (Mercator), 25
see also navigation
marine magnetic anomalies. See magnetic anomalies, marine
Mars, 3 , 54 , 244
Maskelyne, Nevil, 133
Matthews, Drummond, xi, 192–94
Matuyama, Motonori, xi, 158 , 199 , 201
Maxwell, James Clerk, xi, 63 , 93–100, 96
Maxwell’s Equations, 96 , 98 , 220
Treatise on Electricity and Magnetism, 98 , 99
McDougall, Ian, 197 , 198
Mécometrie de l’Eymant (Nautonnier), 42–46
Melloni, Macedonio, 152
Mercanton, Paul, xi, 156–57
Mercator, Gerardus, 24 , 43
Septentrionalium Terrarum, map of, 25
Mercury, 3 , 54 , 244
Mill, H.R., 215
mid-ocean ridge. See ocean ridge
Morley, Lawrence, xi, 185 , 192–94
Muller, Richard, 242
N
Nautonnier, Guillaume de Mécometrie de l’Eymant, 42–46
Navier-Stokes equations, 220 , 238
Navier, Claude, 220
navigation, 12 , 20–31
portolan charts, 21–23, 22
rhumb lines, 21 , 22
see also compass
Neckam, Alexander, xi, 12–13
Néel, Louis, xi, 160 , 163–66, 163, 173
Neptune, 3 , 243
Newton, Sir Isaac, 52–53, 69–70, 138
Norman, Robert, xi, 28–29, 28
nutation, 137 , 139
O
ocean ridge, 186–94, 201 -208
ocean trench, 187 , 188 , 189 , 202
Oldham, Richard Dixon, 143
Oliva, Joan Rizo, 22
portolan chart (Mediterranean Sea), 22
Ørsted, Hans Christian, xii, 79–80
P
P wave. See primary wave
paleomagnetic poles, 177–78
paleomagnetism, 152–60, 165–66, 167–81, 197–212, 232 , 239
paleopoles. See paleomagnetic poles
paramagnetism, 160–61
Peregrinus, Petrus, x, 5 , 16–19, 23–24, 213 , 219
Epistola de Magnete, 16 , 18
Petrus Peregrinus Medal of the European Geosciences Union, The, 18, 19
primary wave (pressure wave, P wave), 141–45, 148 , 149
Pitman III, Walter, 204 , 206 , 211
planetary magnetism, 3 , 54 , 243–44
plate tectonics, 202
Pliny the Elder, 6
Poisson, Siméon-Denis, 118 , 135 , 141 , 220
polar wander, 178–80, 179, 182
polarity, discovery of, 16
polarity chron, 210 , 211 , 212
polarity reversal. See geomagnetic field reversal
polarity timescale. See geomagnetic polarity time scale
Pole Star, 14 , 18 , 26
poloidal field, 233
portolan charts, 21–23, 22
> potassium–argon dating, 196–97
precession (of equinoxes), 110 , 137 , 139
pressure wave. See primary wave
proton precession magnetometer, 189–90
R
radiometric dating. See potassium– argon dating
Rebeur-Paschwitz, Ernst von, 140–41, 142–43
rhumb lines, 21 , 22
Richer, Jean, 138
Rikitake, Tsuneji, 227–29
Roberts, Paul, xii, 230–31, 238–39, 235
computer simulation of geomagnetic field, 231–37, 234, 236
Robertson, Edwin (Eddy), 167–68
Rossel, Paul Edouard de, 104
rotating body theory, 221–22
Royal Institution, The, 84–85, 87
Royal Society, The, 49–50, 87 , 127
Runcorn, Keith, xii, 169 , 174–75, 179 , 181–82, 221
S
S wave. See shear wave
Sabine, Edward, xii, 101 , 111 , 119–20, 124–28
geomagnetic intensity, chart of, 109 Saturn, 3 , 242 , 243
Savart, Félix Biot-Savart Law, 81–82
Schuster, Arthur, 216–17, 219
Schwabe, Samuel Heinrich, 127–28, 215–16
seafloor spreading, 189 , 191–94, 193, 201–6, 208–9
secondary wave. See shear wave
secular variation (geomagnetic), 2 , 48–49, 50–62, 151–52, 158 , 173 , 219–20, 222 , 235 , 237
seismic shadow zone, 144–45, 145, 146 , 146, 148 , 149
seismology, 140–50
primary wave (pressure wave, P wave), 141–45, 148 , 149
seismic shadow zone, 144–45, 145, 146 , 146, 148 , 149
seismograms, 147
shear wave (secondary wave, S wave), 142–45
self-reversal, 173–75, 182–83, 184 , 200
Septentrionalium Terrarum, map of (Mercator), 25
Shandan, 10 , 11
shear wave (secondary wave, S wave), 142–45
solar magnetism, 215–16, 217–21
solar wind, 3 , 243
spherical harmonic analysis, 118–23, 121
spreading ridge. See ocean ridge Stevenson, David, 244
Stokes, George Gabriel, 220
Navier-Stokes equations, 220 , 238
subduction zone. See ocean trench
sunspots, 128 , 215–16, 217–19
T
Tarling, Don, 197 , 198
terrella. See lodestone terrella,
Thales of Miletus, xii, 6–8, 7
The Road to Jaramillo (Glen), 201 , 203
Thellier, Émile, xii, 158
Thompson, Sir Benjamin, 85
Thomson, William, 136–37
toroidal field, 233
torsion balance, 71–72, 72, 74 , 75 , 133
transform fault, 202
North Pole, South Pole: The Epic Quest to Solve the Great Mystery of Earth's Magnetism Page 24
