Seismic and wave field exploration
A.A. 2023/2024
Obiettivi formativi
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.
Risultati apprendimento attesi
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.
Periodo: Secondo semestre
Modalità di valutazione: Esame
Giudizio di valutazione: voto verbalizzato in trentesimi
Corso singolo
Questo insegnamento può essere seguito come corso singolo.
Programma e organizzazione didattica
Edizione unica
Responsabile
Periodo
Secondo semestre
Programma
· 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.
Prerequisiti
Physics: knowledge of mechanics and electromagnetism. Mathematics: differential equations, complex numbers, Fourier analysis.
Metodi didattici
Theoretical lectures and practical exercises in python/Matlab, with implementation of simple processing and visualization scripts.
Materiale di riferimento
· 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
Modalità di verifica dell’apprendimento e criteri di valutazione
Oral exam and mandatory home assignments during the lectures (consisting in the development of processing/visualization scripts).
GEO/11 - GEOFISICA APPLICATA - CFU: 6
Esercitazioni pratiche con elementi di teoria: 24 ore
Lezioni: 32 ore
Lezioni: 32 ore