Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-13T04:14:55.415Z Has data issue: false hasContentIssue false

Observations of the Earth's magnetic field made in Edinburgh from 1670 to the present day

Published online by Cambridge University Press:  03 November 2011

D. R. Barraclough
Affiliation:
British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA

Abstract

Magnetic observations made at the same site give valuable information about the time changes (the secular variation) of the geomagnetic field. This paper gives details of all known measurements of the geomagnetic field in and around Edinburgh since the earliest observation of magnetic declination (the difference between true and magnetic north) by George Sinclair in 1670. Early observations of the strength of the field were only relative measurements. Approximate conversion factors are derived to enable these data to be expressed in modern absolute units (nanoteslas). Observed values of declination, inclination and the horizontal intensity of the geomagnetic field are plotted and compared with values computed from mathematical models of the field covering the interval 1690 to 1990, inclusive. The earlier observations were not corrected for the effects of the rapidly varying magnetic fields caused by electric currents in the upper atmosphere. The consequences of this are estimated.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Avann, F. M. & Barraclough, D. R. 1975. Chart of the magnetic declination for the British Isles, epoch 1975.0. REPT INST GEOL SCI, No. 75/10.Google Scholar
Bache, A. D. 1841a. A comparison of the magnetic intensity in Philadelphia, Dublin, and Edinburgh. PROC R IRISH ACAD, 1, 7172.Google Scholar
Bache, A. D. 1841b. Observations of the magnetic intensity at twenty-one stations in Europe. TRANS AMER PHIL SOC, 7, 75–100.CrossRefGoogle Scholar
Barraclough, D. R. 1989. The daily variation of the geomagnetic field in the region of the North Sea, TECH REPT BRIT GEOL SURV WM/89/25C.Google Scholar
Becquerel, A. C. 1840. Traité de I'électricité et du magnétisme. Tome VII: Du magnetisme terrestre. Paris: Firmin Didot Frères.Google Scholar
Bemmelen, W. van 1899. Die Abweichung der Magnetnadel; Beobachtungen, Sacular-Variation, Wertund Isogonensysteme bis zur Mitte des XVIIIten Jahrhunderts. OBSNS R MAGN MET OBS BATAVIA, 21 (Supplement), 1109.Google Scholar
Bloxham, J. & Jackson, A. 1992. Time-dependent mapping of the magnetic field at the core-mantle boundary. J GEOPHYS RES, 97, 19537–63.CrossRefGoogle Scholar
Brewster, D. 1837. A Treatise on Magnetism, forming the Article under that head in the Seventh edition of the Encyclopaedia Britannica. Edinburgh: Adam & Charles Black.Google Scholar
Cafarella, L., De Santis, A. & Meloni, A. 1993. II Catalogo Geomagnetico Storico Italiano. Roma: Istituto Nazionale di Geofisica.Google Scholar
Dunlop, J. 1830. An account of observations made in Scotland on the distribution of the magnetic intensity. TRANS R SOC EDINBURGH, 12, 163.Google Scholar
Evans, F. J. 1872. On the present amount of westerly declination [variation of the compass] on the coast of Great Britain, and its annual changes. PHIL TRANS R SOC LONDON, 162, 319–30.Google Scholar
Felgenträger, W. 1892. Die längste nachweisbare säculare Periode der erdmagnetischen Elemente. Göttingen: Louis Hofer.Google Scholar
Forbes, J. D. 1837. Account of some experiments made in different parts of Europe, on the terrestrial magnetic intensity, particularly with reference to the effect of height. TRANS R SOC EDINBURGH, 14, 129.Google Scholar
Forbes, J. D. 1840. Account of some additional experiments on terrestrial magnetism, made in different parts of Europe in 1837. TRANS R SOC EDINBURGH, 15, 2736.CrossRefGoogle Scholar
Gauss, C. F. 1833. Intensitas vis magneticae terrestris ad mensuram absolutam revocata. Gottingen: S. Dieterich.Google Scholar
Gauss, C. F. 1839. Allgemeine Theorie des Erdmagnetismus. In Gauss, C. F. & Weber, W. (eds) Resultate aus den Beobachtungen des magnetischen Vereins im Jahre 1838, 157. Leipzig: Weidmann.Google Scholar
Hansteen, C. 1819. Untersuchungen tiber den Magnetismus der Erde. Christiania: Lehmann & Gröndahl.Google Scholar
Hansteen, C. 1828. Table of the variations of the magnetic needle, according to the latest observations. EDINBURGH J SCI, 9, 264–75.Google Scholar
Hansteen, C. 1845. Extract from a letter from Professor Hansteen, Christiania, to Professor Forbes, Edinburgh. PROC R SOC EDINBURGH, 1, 388–95.CrossRefGoogle Scholar
McDonald, K. L. 1971. A proposed spherical harmonic analysis program for geomagnetic data. EOS TRANS AMERICAN GEOPHYS UNION, 52, 572–9.CrossRefGoogle Scholar
Malin, S. R. C. 1982. Sesquicentenary of Gauss's first measurement of the absolute value of magnetic intensity. PHIL TRANS R SOC LONDON, A306, 5–8.Google Scholar
Malin, S. R. C. & Barraclough, D. R. 1982. 150th anniversary of Gauss's first absolute magnetic measurement. NATURE, 297, 285.CrossRefGoogle Scholar
Malin, S. R. C. & Barraclough, D. R. 1991. Humboldt and the Earth's magnetic field. Q J R ASTR SOC, 32, 279–93.Google Scholar
Malin, S. R. C. & Bullard, E. 1981. The direction of the Earth's magnetic field at London, 1570–1975. PHIL TRANS R SOC LONDON, A299, 357–423.Google Scholar
Mayaud, P. N. 1973. A hundred year series of geomagnetic data, 1868–1967, indices aa, storm sudden commencements. BULL INT ASSOC GEOMAGN AERON, No. 33.Google Scholar
Nevanlinna, H. & Kataja, E. 1993. An extension of the geomagnetic activity series aa for two solar cycles (18441868). GEOPHYS RES LETT, 20, 2703–06.CrossRefGoogle Scholar
Nevanlinna, H. & Ketola, A. 1993. Magnetic results from Helsinki Magnetic-Meterological Observatory. Part III. Declination 18541889. Geomagnetic Activity 18441880. GEOPHYSICAL PUBLICATIONS, FINNISH METEOROLOGICAL INSTITUTE, No. 33.Google Scholar
O'Beirne, T. H. 1949. Report on Magnetic Survey Work 1947–48. Ordnance Survey (unpublished report).Google Scholar
Rangarajan, G. K. 1989. Indices of geomagnetic activity. In Jacobs, J. A. (ed.) Geomagnetism, Volume 3, 323–84. London: Academic Press.Google Scholar
Raulin, V. 1867. Quelques vues générales sur les variations seculaires du magnetisme terrestre. ACTES SOC LINNEENNE DE BORDEAUX, 26, 192.Google Scholar
Reader, E. R. 1992. UK regional magnetic repeat station network results 1985. TECH REPT BRIT GEOL SURV WM/92/37R.Google Scholar
Reader, E. R. 1993. UK regional magnetic repeat station network results 1990. TECH REPT BRIT GEOL SURV WM/93/33R.Google Scholar
Reader, E. R. 1994. UK regional magnetic repeat station network results 1993. TECH REPT BRIT GEOL SURV WM/94/23R.Google Scholar
Rücker, A. W. & Thorpe, T. E. 1890. A magnetic survey of the British Isles for the epoch January 1, 1886. PHIL TRANS R SOC LONDON, A181, 53328.Google Scholar
Rücker, A. W. & Thorpe, T. E. 1896. A magnetic survey of the British Isles for the epoch January 1, 1891. PHIL TRANS R SOC LONDON, A188, 1661.CrossRefGoogle Scholar
Sabine, E. 1837. Observations on the direction and intensity of the terrestrial magnetic force in Scotland. REPT BRIT ASSOC ADVANCEMENT SCI, 5, 97119.Google Scholar
Sabine, E. 1839. A memoir on the magnetic isoclinal and isodynamic lines in the British Isles, from observations by Professors Humphrey Lloyd and John Phillips, Robert Were Fox, Esq., Captain James Clark Ross, R.N., and Major Edward Sabine. R.A. REPT BRIT ASSOC ADVANCEMENT SCI, 7, 49196.Google Scholar
Sabine, E. 1870. Contributions to terrestrial magnetism. No. XII. The magnetic survey of the British Islands, reduced to the epoch 1842.5. PHIL TRANS R SOC LONDON, 160, 265275.Google Scholar
Sinclair, G. 1683. Natural Philosophy Improven by New Experiments Touching the Mercurial Weather Glass, the Hydroscope, Eclipsis, Conjunctions of Saturn and Jupiter.... Edinburgh.Google Scholar
Smyth, C. P. 1871. Astronomical Observations Made at the Royal Observatory, Edinburgh, Volume XIII for 1860–1869, with Additions to 1871. Edinburgh.Google Scholar
Smyth, C. P. 1877. Astronomical Observations Made at the Royal Observatory, Edinburgh, Volume XIVfor 1870–1877. Edinburgh.Google Scholar
Stewart, B. 1860. On some results of the magnetic survey of Scotland in the years 1857 and 1858, undertaken, at the request of the British Association, by the late John Welsh, Esq., F.R.S. REPT BRIT ASSOC ADVANCEMENT SCI, 28, 167–90.Google Scholar
Taylor, E. G. R. 1954. The Mathematical Practitioners of Tudor and Stuart England. Cambridge: University Press.Google Scholar
Walker, G. W. 1919. The magnetic re-survey of the British Isles for the epoch January 1, 1915. PHIL TRANS R SOC LONDON. A219, 1135.Google Scholar