Main Article Content
In magnetotelluric studies time variations of the horizontal telluric and magnetic field components at the earth's surface are compared to get detailed information of the electrical conductivity structure of the earth's interior. The development of conductivity models from the data demands the thorough estimation of the transfer functions in the frequency domain between the Fourier transforms of the recorded time series. The analytical presentation of the estimated transfer functions allows an individual selection of a number of frequencies for further investigation. Larsen's presentation (Larsen, 1975, 1980) of the transfer functions by single polynomials demands a complicated calculation of confidence limits. Therefore, the transfer functions are presented here by the sum of polynomials which fulfil an orthogonality criterion. The orthogonality criterion allows a rather simple estimation of the frequency-dependentconfidence limits of the transfer functions. The polynomial method is applied to a 100-day record of the magnetic and telluric field variations near Gottingen. As the telluric field is usually partially disturbed during such a long time interval, the polynomial method is extended to treat telluric time series with missing data. The comparison of the smooth polynomial transfer functions with band-averaged estimates yields a good correlation between the estimates as well as between their confidence intervals.
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...)
Goodman, N.R. (1957) On the joint estimation of the spectra, co-spectrum and quadrature spectrum of a two-dimensional stationary Gaussian process. Scientific paper 10, Engineering Statistics Lab., New York University
Jenkins, G., Watts, P. (1968) Spectral analysis and its applications. San Francisco: Holden Day
Larsen, J.C. (1975) Low frequency (0.1-6.0 cpd) electromagnetic study of deep mantle electric conductivity beneath the Hawaiian Islands. Geophys. J. R. Astron. Soc. 43, 17- 46
Larsen, J.C. (1980) Electromagnetic response functions from interrupted and noisy data. J. Geomagn. Geoelectr. 32, 17-46