Two and three dimensional magnetotelluric inversion

Technical Report · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6596744

This paper is an annual progress report. In prior reporting periods, a numerically efficient algorithm to invert large magnetotelluric (MT) data sets for conductive structures has been developed. The method is iterative and approximates lateral derivatives of the electric and magnetic fields inside the model by their values from the previous iteration. The model is made unique by minimizing a function which measures the complexity of the model. The purpose is to find the model with the least structure for a given level of misfit to the data. The method is called the Rapid Relaxation Inverse (RRI). During the past year, effort has been split between improving the two-dimensional (2D) version of our code and developing a three-dimensional (3D) version. The 2D work has involved a thorough study of synthetic data generated from known models with random noise added. This study resulted in the implementation of three stabilization schemes. One which operates in model space and damps efforts by the algorithm to make the model rough. The second operates in data space and down-weights data with large residuals at each iteration. This means that data that is easy to fit will be fit first. 4 refs., 13 figs.

• Research Organization: Washington Univ., Seattle, WA (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: FG06-89ER14064
• OSTI ID: 6596744
• Report Number(s): DOE/ER/14064-1; ON: DE90016187
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
MAGNETOTELLURIC SURVEYS
MATHEMATICAL MODELS
ALGORITHMS
BOUNDARY CONDITIONS
COMPARATIVE EVALUATIONS
COMPUTER GRAPHICS
DATA ACQUISITION SYSTEMS
DISPLAY DEVICES
EFFICIENCY
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
FREQUENCY ANALYSIS
GEOLOGIC AGES
IMAGE PROCESSING
INTERPOLATION
MAGNETIC FIELDS
NOISE
PROGRESS REPORT
RESPONSE FUNCTIONS
SURFACE PROPERTIES
THREE-DIMENSIONAL CALCULATIONS
TWO-DIMENSIONAL CALCULATIONS
COMPUTER OUTPUT DEVICES
COMPUTER-GRAPHICS DEVICES
DOCUMENT TYPES
ELECTRICAL PROPERTIES
ELECTRICAL SURVEYS
ELECTROMAGNETIC SURVEYS
FUNCTIONS
GEOPHYSICAL SURVEYS
MATHEMATICAL LOGIC
NUMERICAL SOLUTION
PHYSICAL PROPERTIES
PROCESSING
SURVEYS
580000* - Geosciences
990200 - Mathematics & Computers