Unit GEOPHYSICAL PROSPECTING

Course
Geosciences for risk and environment management
Study-unit Code
GP004875
Curriculum
Geologia applicata alla salvaguardia e alla pianificazione del territorio
Teacher
Paolo Mancinelli
Teachers
  • Paolo Mancinelli
Hours
  • 57 ore - Paolo Mancinelli
CFU
6
Course Regulation
Coorte 2024
Offered
2024/25
Learning activities
Caratterizzante
Area
Discipline geofisiche
Academic discipline
GEO/10
Type of study-unit
Obbligatorio (Required)
Type of learning activities
Attività formativa monodisciplinare
Language of instruction
Italian
Contents
This course deals with the main geophysical methods to investigate sub-surface.
We will see active prospection methods (e.g. seismic refraction, reflection) and passive methods (e.g. gravity and magnetic anomalies, heat flow) that are used for the characterization at the crustal scale for exploration or research purposes.
We will also see local-scale methods (e.g. MASW, Electrical methods, GPR) that are used for the characterization of construction site and near surface geophysics.
Reference texts
• An Introduction to Applied and Environmental Geophysics – J. M. Reynolds – Wiley-Blackwell
• An introduction to geophysical exploration – P. Kearey et al – Wiley-Blackwell
• Applied geophysics – W. M. Telford et al – Cambridge University press
Educational objectives
The course aims to provide to the students the fundamental knowledge to produce and understand the main geophysical methods to investigate and characterize the sub-surface using active and passive methods such seismic profiles, electric and electromagnetic methods, potential fields anomalies analysis and thermal field analysis at all scales.
Prerequisites
Basic knowledge of physics, trigonometry, magnetic and gravity potential fields, thermal field of the Earth.
Teaching methods
Frontal lectures and exercises
Other information
Slides showed during the lessons will be provided to the students.
Learning verification modality
Learning of the concepts discussed during the lessons will be evaluated with an oral exam after the course is completed. The exam will involve only the themes discussed in the lessons. The questions that will be asked will address the entire program and deal with the most important concepts discussed during lessons and eventual exercises.
Extended program
• Basic concepts on waves, time-domain Vs frequency domain. What is an anomaly, what is noise, SNR
• Seismic waves: volume and surface waves
• Wavefront and raypath, acoustic impedence, diffraction and convloution.
• Time-space relations for direct, refracted and reflected waves in horizontal and parallel strata
• Time-space relations for direct, refracted and reflected waves in inclined stratification.
• Refraction seismic, Snell law, critical refraction, reflection coefficient, limitations of the refraction method
• Reflection seismic, Common Shot Gathers, Common Mid Point.
• Precautions to perform a proper seismic acquisition.
• Fundamentals of seismic processing (NMO, Stacking, deconvolution, migration, depth conversion).
• Seismic velocities of rocks, methods for determination and importance of the velocity model.
• Surface waves, dispersion, main characteristics of the surface waves and seismostratigraphic characterization of construction sites as defined in the NTC2018 law.
• Surface waves methods: MASW, HVSR. Main characteristics, limitations and advantages.
• Electrical methods: resistivity of rocks, • Basic concepts on waves, time-domain Vs frequency domain. What is an anomaly, what is noise, SNR
• Seismic waves: volume and surface waves
• Wavefront and raypath, acoustic impedence, diffraction and convloution.
• Time-space relations for direct, refracted and reflected waves in horizontal and parallel strata
• Time-space relations for direct, refracted and reflected waves in inclined stratification.
• Refraction seismic, Snell law, critical refraction, reflection coefficient, limitations of the refraction method
• Reflection seismic, Common Shot Gathers, Common Mid Point.
• Precautions to perform a proper seismic acquisition.
• Fundamentals of seismic processing (NMO, Stacking, deconvolution, migration, depth conversion).
• Seismic velocities of rocks, methods for determination and importance of the velocity model.
• Surface waves, dispersion, main characteristics of the surface waves and seismostratigraphic characterization of construction sites as defined in the NTC2018 law.
• Surface waves methods: MASW, HVSR. Main characteristics, limitations and advantages.
• Electrical methods: resistivity of rocks, electrodes configuration for resistivity measurements, apparent res. Vs real res. ERT inversions
• Basic notions about spontaneous potential methods, induced polarization, TEM and TDEM methods and magnetotelluric methods.
• Ground Penetrating Radar (GPR), relation between GPR pulse velocity and EM properties of materials, resolution vs penetrationn of GPR signal as a function of antenna’s frequency, limitations due to high-conductivity materials, range of applications of GPR instruments.
• Fundamentals of geothermics. Heat flux, heat transfer, Fourier equation, thermal conductivity of natural materials, geothermal resources development and usage.
• Magnetic anomalies, magnetization and induced field, ACurie temperature -> Curie depth, magnetic susceptibility, paleomagnetism.
• Analysis of anomaly maps: intensity and wavelength of anomalies.
• Gravity anomalies: gravity data corrections, density of rocks, principles for interpretation of gravity anomalies.
• Anomalies filtering, forward modeling, inverse modeling.
• 4D geophysics: its significance, applications and capabilities.
• Laboratory exercise: 2D and 3D integrated modeling of geological and geophysical data for the crustal-scale investigation.
• 4D geophysics: its significance, applications and capabilities.
Obiettivi Agenda 2030 per lo sviluppo sostenibile
The Course deals with the following Sustainable Development Goals (SDGs) of the ONU 2030 Agenda:
- Goal 7.Affordable and Clean Energy.
- Goal 12.Responsible Consumption and Production
- Goal 15.Life On Land. Protect, restore and promote the sustainable terrestrial ecosystems.
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