The magnetotelluric coast effect near a dyke or long promontory

Authors

• J. R. Blake
• Daniel W. Swift

Files

Description

The magnetic and telluric fields near a vertical, infinitely deep dyke in an otherwise homogeneous plane medium are calculated. The approximate constancy of the horizontal, surface magnetic field at low frequencies is used as a boundary condition, following Weaver (1963b). Both “polarizations” of the surface electromagnetic field are considered, according to whether the electric or magnetic fields are parallel to the strike. The polarization ellipses of the telluric field and the vertical magnetic field are computed as functions of the conductivity ratio, and dyke thickness, for various observing positions and frequencies, and the fields are compared with similar calculations based on Weaver’s simple fault model. An extension is outlined and the analytical results presented for the case where both ocean and land are underlain by a non-conducting basement. The work of Rankin (1962) is thus extended to cover both polarization orientation of the surface field.

Publication Date

10-17-1967

Keywords

Geomagnetism

Recommended Citation

Blake, J. R. and Swift, Daniel W., "The magnetotelluric coast effect near a dyke or long promontory" (1967). GI Reports. 179.
https://scholarworks.alaska.edu/uaf_gi_reports/179

Handle

http://hdl.handle.net/11122/15615