Seismic and Wave Field Exploration
A.Y. 2023/2024
Learning objectives
Knowledge and understanding: learn the basic knowledge of seismic methods and georadar, with emphasis on data acquisition and processing in exploration seismology; acquire the terminology pertinent to seismic methods and georadar; learn how to implement simple scripts for data processing.
Applying knowledge and understanding: analyze the problems found in real land and marine reflection seismic data and to propose suitable solutions for the processing and, possibly, for the acquisition; approach correctly the design and the implementation of refraction seismic, surface wave analysis and georadar in applied geophysics; implement simple scrips for processing wave field data.
Applying knowledge and understanding: analyze the problems found in real land and marine reflection seismic data and to propose suitable solutions for the processing and, possibly, for the acquisition; approach correctly the design and the implementation of refraction seismic, surface wave analysis and georadar in applied geophysics; implement simple scrips for processing wave field data.
Expected learning outcomes
Making judgements: the acquired knowledge allows to critically evaluate the results obtained at the end of processing of seismic and georadar data. For each processing step, the student is able to evaluate the quality of the processing and the limits of applicability and possible pitfalls of the processing procedures.
Communication skills: The student is able to clearly communicate the topics of reflection and refraction seismic, surface wave analysis and georadar; furthermore, the student is able to clearly explain the issues related to processing and acquisition in seismic and wave field exploration, and to illustrate possible solutions to tackle these issues.
Learning skills: Give the student the ability to learn autonomously topics that can not be dealt with during the lessons due to the limited time available, and also give him/her the ability to deepen the ones discussed.
Communication skills: The student is able to clearly communicate the topics of reflection and refraction seismic, surface wave analysis and georadar; furthermore, the student is able to clearly explain the issues related to processing and acquisition in seismic and wave field exploration, and to illustrate possible solutions to tackle these issues.
Learning skills: Give the student the ability to learn autonomously topics that can not be dealt with during the lessons due to the limited time available, and also give him/her the ability to deepen the ones discussed.
Lesson period: Second semester
Assessment methods: Esame
Assessment result: voto verbalizzato in trentesimi
Single course
This course can be attended as a single course.
Course syllabus and organization
Single session
Responsible
Lesson period
Second semester
Course syllabus
· Basic principles of wave field exploration: wave equation and wave propagation; impedance contrast and reflection/transmission coefficients; Impulse response and Green's theorem; reflectivity and convolutional model for synthetic traces; Fourier transform, convolution, correlation, autocorrelation and related properties; minimum phase wavelets and their properties; sampling rate, aliasing and Nyquist theorem.
· Acquisition of seismic data: impulsive sources and vibroseis; geophones and hydrophones; attenuation processes; acquisition layout in reflection seismic, multi-fold acquisition, common-mid-point (CMP) gathers; acquisition layout in refraction seismic and surface wave analysis.
· Construction of reflection seismic sections: gain correction; deconvolution; frequency-domain filtering and F-K analysis; static corrections; velocity analysis and Normal Moveout correction; stack and zero-offset sections; basic migration concepts and applications.
· Analysis of refraction and surface wave seismic data: traveltimes for horizontal and dipping layers; intercept times and plus-minus method (Generalized Reciprocal Methods); principles and measurement procedures in Multichannel analysis of surface waves (MASW) and Horizontal-to-vertical spectral ratio (HVSR).
· Georadar: similarities and differences between seismic and electromagnetic wave propagation; application of reflections seismic methods for the analysis of georadar data.
· Acquisition of seismic data: impulsive sources and vibroseis; geophones and hydrophones; attenuation processes; acquisition layout in reflection seismic, multi-fold acquisition, common-mid-point (CMP) gathers; acquisition layout in refraction seismic and surface wave analysis.
· Construction of reflection seismic sections: gain correction; deconvolution; frequency-domain filtering and F-K analysis; static corrections; velocity analysis and Normal Moveout correction; stack and zero-offset sections; basic migration concepts and applications.
· Analysis of refraction and surface wave seismic data: traveltimes for horizontal and dipping layers; intercept times and plus-minus method (Generalized Reciprocal Methods); principles and measurement procedures in Multichannel analysis of surface waves (MASW) and Horizontal-to-vertical spectral ratio (HVSR).
· Georadar: similarities and differences between seismic and electromagnetic wave propagation; application of reflections seismic methods for the analysis of georadar data.
Prerequisites for admission
Physics: knowledge of mechanics and electromagnetism. Mathematics: differential equations, complex numbers, Fourier analysis.
Teaching methods
Theoretical lectures and practical exercises in python/Matlab, with implementation of simple processing and visualization scripts.
Teaching Resources
· Methods of Seismic Data Processing, Gary F. Margrave (https://www.crewes.org/ResearchLinks/FreeSoftware/)
· Numerical Methods of Exploration Seismology with algorithms in MATLAB, Gary F. Margrave (https://www.crewes.org/ResearchLinks/FreeSoftware/)
· Seismic data analysis, Oz Yilmaz, investigation in geophysics no.10, SEG
· Numerical Methods of Exploration Seismology with algorithms in MATLAB, Gary F. Margrave (https://www.crewes.org/ResearchLinks/FreeSoftware/)
· Seismic data analysis, Oz Yilmaz, investigation in geophysics no.10, SEG
Assessment methods and Criteria
Oral exam and mandatory home assignments during the lectures (consisting in the development of processing/visualization scripts).
GEO/11 - APPLIED GEOPHYSICS - University credits: 6
Practicals with elements of theory: 24 hours
Lessons: 32 hours
Lessons: 32 hours