The geophysical prospecting is a technique to investigate internal structure of the earth from the geophysical observations at the earth's surface. In this class, students learn about the basic theory and technical background of geophysical techniques using the electromagnetic field, and deepen their understanding through applications to earth science.
[Goal] At the end of this course, students will learn about the basics about the geophysical prospecting techniques to infer the internal structure of the earth, particularly about the technique using the electromagnetic induction in the earth. They will learn the measuring method of electromagnetic fields, a method of analysis, and theories of a forward model calculation and of an inverse model calculation for complicated structures. Furthermore, we aim at understanding the application of these methods to earth sciences.
[Theme] Students will learn the basics on "resistivity of the rock", "variation sources of the natural electromagnetic field", "analysis of the random signal", "forward calculation of electromagnetic response against complicated resistivity structure", and "inverse problem".
Geophysical prospecting, electromagnetic exploration method, electrical resistivity, forward problem, inverse problem
Intercultural skills | Communication skills | Specialist skills | Critical thinking skills | Practical and/or problem-solving skills |
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Attendance is checked at every lecture. In the latter half of the course, each student introduces an associated academic paper.
Course schedule | Required learning | |
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Class 1 | Electrical property of the rock and the DC resistivity method | Learn about the basic electrical property of the rock, and about the principle and measuring method of the DC resistivity method |
Class 2 | Formulation of the inverse problem: introduction | Learn about the description of inverse theory, probability density function, and error propagation |
Class 3 | Natural electromagnetic disturbances, discovery of electrical conductivity anomaly, and calculation of magnetotelluric response function | Learn about historical background of electromagnetic induction in the earth |
Class 4 | Formulation of the inverse problem: linear problem and the least square solution | Learn about a linear problem and the least square solution in the formulation of inverse problem |
Class 5 | Electromagnetic induction in the layered earth and two-dimensional earth | Learn about the theory of electromagnetic induction in the layered earth and the two-dimensional earth |
Class 6 | Formulation of the inverse problem: solution by the generalized inverse matrix, and by the maximum likelihood method | Learn about the solution by the generalized inverse matrix and by the maximum likelihood method in the formulation of inverse problem |
Class 7 | Electromagnetic induction in the three-dimensional earth、and galvanic distortion | Learn about the theory of electromagnetic induction in the three-dimensional earth, and about the cause of galvanic distortion and its correction method |
Class 8 | Formulation of the inverse problem: the solution of non-linear problem | Learn about the solution of a non-linear problem in the formulation of inverse problem |
Class 9 | Electromagnetic induction using the controlled source | Learn about the theory of electromagnetic induction using the controlled source |
Class 10 | Presentation by students: (1) papers related to the earthquake/volcano/electromagnetic induction/inverse problem | Students introduce the papers related to the earthquake/volcano/electromagnetic induction/inverse problem |
Class 11 | Presentation by students: (2) papers related to the earthquake/volcano/electromagnetic induction/inverse problem | Students introduce the papers related to the earthquake/volcano/electromagnetic induction/inverse problem |
Class 12 | Presentation by students: (3) papers related to the earthquake/volcano/electromagnetic induction/inverse problem | Students introduce the papers related to the earthquake/volcano/electromagnetic induction/inverse problem |
Class 13 | Presentation by students: (4) papers related to the earthquake/volcano/electromagnetic induction/inverse problem | Students introduce the papers related to the earthquake/volcano/electromagnetic induction/inverse problem |
Class 14 | Presentation by students: (5) papers related to the earthquake/volcano/electromagnetic induction/inverse problem | Students introduce the papers related to the earthquake/volcano/electromagnetic induction/inverse problem |
Class 15 | Presentation by students: (6) papers related to the earthquake/volcano/electromagnetic induction/inverse problem | Students introduce the papers related to the earthquake/volcano/electromagnetic induction/inverse problem |
None.
Lecture notes are provided at the time of every class.
Reference book on inverse problem: W. Menke, "Geophysical Data Analysis: Discrete Inverse Theory, 3rd Edition"
No examination. The attendance to lectures is necessary. Students will be assessed by an evaluation of presentation made by each student. Participation in the discussion is also considered.
None