International Geomagnetic Reference Field: the third generation.
Reads0
Chats0
TLDR
The International Geomagnetic Reference Field (IGRF) was revised in 1981 by the International Association of Geomagnetism and Aeronomy (IAGFA) as discussed by the authors.Abstract:
In August 1981 the International Association of Geomagnetism and Aeronomy revised the International Geomagnetic Reference Field (IGRF). It is the second revision since the inception of the IGRF in 1968. The revision extends the earlier series of IGRF models from 1980 to 1985, introduces a new series of definitive models for 1965-1975, and defines a provisional reference field for 1975-1980. The revision consists of: (1) a model of the main geomagnetic field at 1980.0, not continuous with the earlier series of IGRF models, together with a forecast model of the secular variation of the main field during 1980-1985; (2) definitive models of the main field at 1965.0, 1970.0, and 1975.0, with linear interpolation of the model coefficients specified for intervening dates; and (3) a provisional reference field for 1975-1980, defined as the linear interpolation of the 1975 and 1980 main-field models. The new models are series of solid spherical harmonics up to and including the tenth degree and order for the main-field models, and up to and including the eighth degree and order for the secular variation model. The models were derived from three sets of proposed models by taking weighted means. The weights were chosen according to the apparent accuracy of the proposed models. A brief history of the IGRF, a review of basic formulas, and a set of world contour maps of the geomagnetic elements based on the IGRF 1980 model are included.read more
Citations
More filters
Journal ArticleDOI
Heat flow from the Earth's interior: Analysis of the global data set
TL;DR: In this paper, a new estimate of the Earth's heat loss based on a new global compilation of heat flow measurements comprising 24,774 observations at 20,201 sites is presented, which when areally weighted yield a global mean of 87 mW m -2 and a global heat loss of 44.2 x 10 2 W, an increase of some 4-8% over earlier estimates.
Journal ArticleDOI
International Geomagnetic Reference Field: the 12th generation
Erwan Thébault,Christopher C. Finlay,Ciaran Beggan,Patrick Alken,Patrick Alken,Julien Aubert,Olivier Barrois,François Bertrand,T. Bondar,A. Boness,Laura Brocco,Elisabeth Canet,Aude Chambodut,Arnaud Chulliat,Arnaud Chulliat,Pierdavide Coïsson,François Civet,Aimin Du,Alexandre Fournier,Isabelle Fratter,Nicolas Gillet,Brian Hamilton,Mohamed Hamoudi,Mohamed Hamoudi,Gauthier Hulot,Thomas Jager,Monika Korte,Weijia Kuang,Xavier Lalanne,Benoit Langlais,Jean-Michel Leger,Vincent Lesur,F. J. Lowes,Susan Macmillan,Mioara Mandea,Chandrasekharan Manoj,Chandrasekharan Manoj,Stefan Maus,Nils Olsen,Valeriy G. Petrov,Victoria Ridley,Martin Rother,Terence J. Sabaka,Diana Saturnino,Reyko Schachtschneider,Olivier Sirol,Andrew Tangborn,Alan Thomson,Lars Tøffner-Clausen,Pierre Vigneron,Ingo Wardinski,Tatiana I. Zvereva +51 more
TL;DR: The 12th generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014 by the Working Group V-MOD appointed by the International Association of Geomagnetism and Aeronomy (IAGA) as discussed by the authors.
Journal ArticleDOI
International Geomagnetic Reference Field: the eleventh generation
Christopher C. Finlay,Stefan Maus,Ciaran Beggan,T. Bondar,Aude Chambodut,T. Chernova,Arnaud Chulliat,V. Golovkov,Brian Hamilton,Mohamed Hamoudi,Richard Holme,Gauthier Hulot,Weijia Kuang,Benoit Langlais,Vincent Lesur,F. J. Lowes,H. Lühr,Susan Macmillan,Mioara Mandea,S. Mclean,C. Manoj,Michel Menvielle,Ingo Michaelis,Nils Olsen,Jan Rauberg,Martin Rother,Terence J. Sabaka,Andrew Tangborn,Lars Tøffner-Clausen,Erwan Thébault,Alan Thomson,Ingo Wardinski,Zigang Wei,Tatiana I. Zvereva +33 more
Abstract: The eleventh generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2009 by the International Association of Geomagnetism and Aeronomy Working Group V-MOD. It updates the previous IGRF generation with a definitive main field model for epoch 2005.0, a main field model for epoch 2010.0, and a linear predictive secular variation model for 2010.0–2015.0. In this note the equations defining the IGRF model are provided along with the spherical harmonic coefficients for the eleventh generation. Maps of the magnetic declination, inclination and total intensity for epoch 2010.0 and their predicted rates of change for 2010.0–2015.0 are presented. The recent evolution of the South Atlantic Anomaly and magnetic pole positions are also examined.
Journal ArticleDOI
The historical development of the magnetic method in exploration
Misac N. Nabighian,V.J.S. Grauch,R. O. Hansen,Thomas R. LaFehr,Yaoguo Li,J. W. Peirce,Jeffrey D. Phillips,M. E. Ruder +7 more
TL;DR: The magnetic method is the primary exploration tool in the search for minerals, oil and gas, geothermal resources, and groundwater, and for a variety of other purposes such as natural hazards assessment, mapping impact structures, and engineering and environmental studies as discussed by the authors.
Journal ArticleDOI
The Cenozoic subduction history of the Pacific margin of the Antarctic Peninsula: ridge crest–trench interactions
TL;DR: In this paper, magnetic anomaly identifications W of the Shackleton Fracture Zone show 5 spreading sections, separated by fracture zones, and the tendency of the subducting plate to continue sinking probably initiated the opening of the Bransfield Strait.
References
More filters
Journal ArticleDOI
The MAGSAT mission
TL;DR: In this article, the cesium-vapor scalar and fluxgate vector magnetometers aboard the Magsat spacecraft have together measured the earth's magnetic field magnitude to accuracies better than 2 nT, and the magnitude of each field component to better than 6 nT.
Journal Article
Some new methods in geomagnetic field modeling applied to the 1960-1980 epoch.
TL;DR: In this paper, a spherical harmonic model is derived with degree and order 13 in its constant and first time derivative terms, six in its second derivative terms and four in its third derivative terms.
Journal ArticleDOI
Some New Methods in Geomagnetic Field Modeling Applied to the 1960-1980 Epoch
TL;DR: In this article, a spherical harmonic model is derived with degree and order 13 in its constant and first time derivative terms, six in its second derivative terms and four in its third derivative terms.
Journal ArticleDOI
A Proposed International Geomagnetic Reference Field for 1965-1985
TL;DR: A set of spherical harmonic models describing the Earth's main magnetic field from 1965 to 1985 has been developed and is proposed as the next revision of the International Geomagnetic Reference Field (IGRF) as discussed by the authors.
Journal ArticleDOI
The IGS Proposal for the New International Geomagnetic Reference Field
TL;DR: This work proposed for adoption as the new International Geomagnetic Reference Field a series of main-field models to degree and order ten for 1965, 1970, 1975, and 1980, and a secular variation model for the interval 1980 to 1985.
Related Papers (5)
The near‐Earth magnetic field at 1980 determined from Magsat data
Robert A. Langel,R. H. Estes +1 more