1. 1. Introduction to Geophysics Ali O. Oncel [email_address] Department of Earth Sciences KFUPM Lecture 2 Overview
2. 2. Geophysics
   • Identify Geologic Problem
   • Survey Plan
   • Data Acquisition
   • Data Reduction
   • Data Analysis
   • Modeling
   • Write Report
   Photos fromhttp://www.eegs.org/whatis/
3. 3. What is Geophysics?
   • Application of physics to studies of the Earth,Moon, and other planets
   • Includes Earth, Atmosphere, Oceans, Planetarysystems
4. 4. What is Geophysics?
   • Solid-earth geophysics which isthe study of the earth by quantitative physical methods, thus excludingportions of other subjects
   • Exploration geophysicsis the use of seismic, gravity,magnetic, electrical, electromagnetic, etc.,methods in the search for oil, gas, minerals,water,etc., with the objective of economic exploitation.
5. 5. Examples of Geophysics
   • Pure and Applied Geophysics
   • Solid Earth
   • Surface Geophysics
6. 6. Applied Geophysics (economic objectives)
   • Exploration Geophysics
   • Engineering Geophysics
   • Environmental Geophysics
   • Groundwater Geophysics
   • Archaeo Geophysics
   • Forensics
7. 7. Applications?
   • Approach to earthquake hazards and ground survey
   • Plate tectonics, the study of the interiorstructure of the earth
   • Human's ability to exploit natural resources
   • Engineering
   • Environmental
   • Hydrological
   http://seg.org/you-geo/definition.shtml
8. 8. Examples of geophysical methods?
   • Gravity
   http://www.vibra-tech-inc.com/content.asp?ID=magnetics_gravity
9. 9. Examples of geophysical methods?
   • Magnetics
   http://www.vibra-tech-inc.com/content.asp?ID=magnetics_gravity
10. 10. Examples of geophysical methods? Seismics a. Reflection b. Refraction c. Surface or borehole
11. 11. Examples of geophysical methods? Ground Penetrating Radar
12. 12. Examples of geophysical methods?
    • Resistivity
13. 13. Geophysical Methods
    • May not yield complete answer or unique solution; Non-uniqueness of forward modeling
    • Many solutions, but which ones are nonsense, which are plausible
    • Interpret within physical constraints & geological framework
14. 14. Geophysics and Geology
    • Geology places constraints on geophysical models
    • Geophysics places constraints on geologic interpretations
15. 15. Planning a Survey - Spatial Aliasing
16. 16. Two and Three Dimensions Location of Profiles
17. 17. Common Sources of Geophysical Noise
18. 18. Data Processing - Elimination of Noise
19. 19. Displaying Data
20. 20. Summary
    • Geophysics
    • Applied (Environmental) Geophysics
    • Gravity, Magnetic, Seismic, GPR & Resistivity
    • Selection of Proper Technique
    • Designing a Geophysical Survey