PW2D finite element program for solution of magnetotelluric responses of two-dimensional earth resistivity structure. User documentation

Technical Report · Sun Sep 01 04:00:00 EDT 1985

OSTI ID:5015685

Wannamaker, P E; Stodt, J A; Rijo, L

Algorithm PW2D is a finite element program for simulation of magnetotelluric responses of two-dimensional earth resistivity structure. Linear interpolation of the unknown field parallel to strike over triangular subdomains is utilized in conjunction with the Galerkin method of basis weighting to derive a system of linear equations which approximates the governing Helmholtz equation. From the field parallel to strike, the auxiliary vertical and transverse fields obtain from a numerical approximation to Maxwell's equations. Both transverse electric (TE) and transverse magnetic (TM) modes of plane-wave excitation can be modeled. The algorithm described herein unlike previous versions of the program solves directly for secondary variations in the field parallel to strike, plus the subsequent auxiliary fields. This approach has circumvented a difficulty with numerical precision at low frequencies observed in total field solutions for the TM mode especially, but also for the TE mode. 14 refs., 18 figs.

• Research Organization: Utah Univ. Research Inst., Salt Lake City (USA). Earth Sciences Lab.
• DOE Contract Number: AC03-84SF12196
• OSTI ID: 5015685
• Report Number(s): DOE/SAN-12196-13; ESL-158; ON: DE86002009
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580203* -- Geophysics-- Geophysical Survey Methods-- (1980-1989)
ALGORITHMS
COMPUTER CODES
COMPUTERIZED SIMULATION
ELECTRICAL SURVEYS
ELECTROMAGNETIC SURVEYS
FINITE ELEMENT METHOD
GEOPHYSICAL SURVEYS
MAGNETOTELLURIC SURVEYS
MATHEMATICAL LOGIC
NUMERICAL SOLUTION
P CODES
SIMULATION
SURVEYS
TWO-DIMENSIONAL CALCULATIONS