Main Article Content
The usefulness of long-wavelength potential field anomalies in lithospheric interpretation is greatly increased with spherical Earth modeling techniques. Gauss-Legendre quadrature integration is used to calculate the anomalous potential of gravity and magnetic fields and their spatial derivatives on a spherical Earth for an arbitrary body represented by an equivalent point source distribution of gravity poles or magnetic dipoles. The distribution of equivalent point sources is determined directly from the coordinate limits of the source volume. Variable integration limits for an arbitrarily shaped body are derived from interpolation of points which approximate the body's surface envelope. The versatility of the method is enhanced by the ability to treat physical property variations within the source volume and to consider variable magnetic fields over the source and observation surface. A number of examples verify and illustrate the capabilities of the technique, including preliminary modeling of potential field signatures for Mississippi embayment crustal structure at satellite elevations.
Authors who publish with this journal as of Vol. 63 agree to the following terms:
a. Authors share the copyright with this journal in equal parts (50% to the journal, 50% to the lead author), and grant the journal right of first publication, with the work after publication simultaneously licensed under Creative Commons Attribution License CC BY-NC-ND 4.0 that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.
b. Authors may enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal, and a reference to this copyright notice.
c. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) during the submission process, as this can lead to productive exchanges and earlier and greater citation of published work and better sales of the copyright.
Authors retain copyright and grant the Journal of Geophysics right of first publication, with the work three years after publication simultaneously licensed under the Creative Commons BY-NC-ND 4.0 License that allows others to share the work (with an acknowledgment of the work's authorship and initial publication in this journal), except for commercial purposes and for creating derivatives.
Authors can enter into separate, additional, but non-commercial contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository, but not publish it in a book), with an acknowledgment of its initial publication in this journal.
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) before and during the submission process, as that can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
This journal is one of a handful of scholarly journals that publish original scientific works under CC BY-NC-ND 4.0 - the only Creative Commons license affording the authors' intellectual property absolute worldwide protection.
Journal of Geophysics is published under the scholar-publishers model, meaning authors do not surrender their copyright to us. Instead, and unlike corporate publishers like Elsevier or Springer Nature that resell copyright to third-parties for up to $80,000 (per paper, per transaction!), the Journal of Geophysics authors share copyright equally with this journal.
Therefore, all the proceeds from reselling copyright to third parties get shared to equal parts (50% to the journal, 50% to the lead author). Under the Berne Convention, this protection is an inheritable right that lasts for as long as the rightsholder lives + 50 years.
By submitting to this journal, the lead author, on behalf of all co-authors, grants permission to this journal to represent all co-authors in negotiating copyright sales and collecting proceeds. The lead author should negotiate with his/her co-authors the modalities of distributing the lead author's portion of the proceeds. Usually, this is per pre-agreed percentage of each co-author's contribution to creating the copyrighted work. (more...)
Bhattacharyya, B.K. (1978) Computer modeling in gravity and magnetic interpretation. Geophysics 43:912-929
Cain, J.C., Hendricks, S.J., Langel, R.A., Hudson, W.V. (1967) A proposed model for the International Geomagnetic Reference Field, 1965. J. Geomagn. Geoelectr. 19:335-355
Carnahan, B., Luther, H.A., Wilkes, J.O. (1969) Applied Numerical Methods. J. Wiley and Sons, New York
Cordell, L. (1977) Regional positive gravity anomaly over the Mississippi Embayment. Geophys. Res. Lett. 4:285-287
Ervin, C.P., McGinnis, L.D. (1975) Reelfoot rift: Reactivated precursor to the Mississippi Embayment. Geol. Soc. Am. Bull. 86:1287-1295
Frese, R.R.B. von, Hinze, W.J., Braile, L.W., Luca, A.J. (1980) Spherical earth gravity and magnetic anomaly modeling by Gauss-Legendre quadrature integration. NASA Rept NAS5-25030
Hall, D.H. (1974) Long-wavelength aeromagnetic anomalies and deep crustal magnetization in Manitoba and Northwestern Ontario, Canada. Pageoph. 40:403-430
Heiskanen, W.A., Mortiz, H. (1967) Physical Geodesy. W.H. Freeman and Co., San Francisco
Ku, C.C. (1977) A direct computation of gravity and magnetic anomalies caused by 2- and 3-dimensional bodies of arbitrary shape and arbitrary magnetic polarization by equivalent point method and a simplified cubic spline. Geophysics 42:610-622
Langel, R.A. (1979) Near-earth satellite magnetic field measurements: A prelude to Magsat. EOS (Trans. Am. Geophys. Union) 60:667-668
McCamy, K., Meyer, R.P. (1966) Crustal results of fixed multiple shots in the Mississippi Embayment; In: Steinhart, J.S., Smith, T.J. (Eds.) The Earth Beneath the Continents, Am. Geophys. Union Geophys. Monogr. 19:370-381
Sass, J.H., Diment, W.H., Lachenbruch, A.H., Marshall, B.V., Munroe, R.J., Moses, T.H., Jr., Urban, T.C. (1976) A new heat-flow contour map of the conterminous United States. USGS, Open-file Rept. 76-756
Shuey, R.T., Schellinger, D.K., Johnson, E.H., Alley, L.B. (1973) Aeromagnetics and the transition between the Colorado Plateau and the Basin and Range Provinces. Geology 1:107-110
Stroud, A.H., Secrest, D. (1966) Gaussian Quadrature Formulas. Prentice-Hall, New Jersey
Talwani, M., Ewing, M. (1960) Rapid computation of gravitational attraction of three-dimensional bodies of arbitrary shape. Geophysics 25:203-225
Talwani, M. (1965) Computation with the help of a digital computer of magnetic anomalies caused by bodies of arbitrary shape. Geophysics 30:797-817
Warren, D.H., Healy, J.H. (1973) Structure of the crust in the conterminous United States. Tectonophysics 20:203-213
Wasilewski, P.J., Thomas, H.H., Mayhew, M.A. (1979) The Moho as a magnetic boundary, NASA Rept. NASA-GSFC TM80245
Woollard, G.P., Joesting, H.R. (1964) Bouguer gravity anomaly map of the United States. Am. Geophys. Union and U.S. Geological Survey, scale 1:2,500,000