Knowledge and understanding: Acquire the knowledge concerning the main geophysical methods for near surface exploration. Learn the basic information of acquisition, analysis and processing of the corresponding data. Applying knowledge and understanding: The knowledge that has been learnt allows to apply in various contexts the different methodologies studied, including analysis and processing of the geophysical data.
Expected learning outcomes
Making judgements: The student is able to evaluate autonomously the geophysical methodologies that can be applied for near surface exploration, knowing the advantages, the disadvantages and the limitations. He/Her knows the procedures to process the acquired geophysical data, and can formulate judgements on the correctness and accuracy of the steps applied. Communication skills: The student is able to clearly communicate to third party the topics of the near surface exploration, the problems to tackle and the possible solutions. He/her can easily interact with the experts in this field for what concerns the procedures for the acquisition, analysis and processing of the available data. 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
(In case of multiple editions, please check the period, as it may vary)
· Gravity surveying: Outlines of the Earth's gravity field and of the density of rocks; field measurement procedures and gravimetric corrections to estimate the Bouguer's anomaly for micro-gravity survey; examples of anomalies on real data. · Electrical surveying: Electrical conduction in rocks; Ohm's law, Archie's law; electrical field generated by a point electrode; electrical quadrupole and apparent resistivity; arrays used and sensitivity function (Fréchet derivatives). Vertical electrical soundings; constant separation traverse; electrical resistivity tomography (ERT); Examples of ERT inversion. · Seismic surveying: Elements on the wave equation and on the body and surface waves; seismic wave velocities in rocks. refraction seismic: traveltimes for horizontal and dipping layers; intercept times and plus-minus method (Generalized Reciprocal Methods). Example of processing on real data. SH-wave reflection seismic: principles, acquisition, multifold coverage, building of a SH-wave stack section. Example on real data. Multichannel analysis of surface waves (MASW): principles and example of application. · Ground Penetrating Radar (GPR): the electromagnetic field; the absolute and relative permittivity; reflection and transmission coefficient of electromagnetic waves; directivity function of receiving and transmitting antennas; vertical and lateral resolution; spatial aliasing; the radargram; diffraction hyperbolae. Radargram examples on real data.