Introduction to the physics of the Earth and glossary
The solar system
Historical background; Elements of physics (Angular velocity, Centripetal and centrifugal force, Angular momentum, Moments of inertia, potential energy, kinetic energy, law of conservation of angular momentum and kinetic energy, doppler effect, electromagnetic spectrum; length units used in astronomy, motions of precession and nutation); Expansion and age of the universe (Hubble's law); Parallax method; Laws of Kepler with proof of the second and third law. Titius-Bode law; Distribution of angular momentum in the solar system; Terrestrial Planets and Giant Planets: main features and differences with respect to the planet Earth; Earth evolution. Differentiation of the Solid Earth and origin of the Atmosphere and Oceans; origin of biological activity and development of the atmosphere. Terrestrial orbital motions and Milankovich cycles.
The physical fields of the planet Earth Summaries of mathematics (nabla operator, cylindrical and spherical Polar coordinate systems), References of physics (flux of a field; Coulomb force, Electric field, comparison with the law of universal gravitation, magnetic field, force of Lorent, lines of a magnetic field, comparison between electric and magnetic field)
a) Gravitational field and gravimetry. The gravitational field: fundamental properties. Earth's gravitational field in the hypothesis of spherical symmetry. Force of gravity; The Geopotential; Mc Cullogh theorem; The geoid and geoid approximations. Gravimetry. Operating principles of absolute and relative gravimeters. Gravimetric measurements. Corrections for tides and drift effects. Compensation of measures and anomalies: latitude corrections, free air (Faye), Piastra (of Bouger), topographic (Hammer method), Eötvö. Calculation of the anomaly generated by a hollow and full sphere; calculation of the anomaly generated by an undefined horizontal cylinder; calculation of the anomaly related to a vertical fault. Breakdown into regional and local anomalies; Interpretation of local and geodynamic gravity anomalies. Isostasia: Pratt and Airy models and examples in Italy and in the world.
b) Magnetic field and magnetometry. Historical outline, Magnetic field: fundamental properties. Magnetic potential and Gauss coefficients. A global model of the field: International Geomagnetic Reference Field (IGRF). Main magnetic field, external and induced. Temporal variations of the magnetic field: polarity inversions, secular variations, daily variations, magnetic storms. The magnetosphere. Diamagnetic, paramagnetic and ferromagnetic substances. Curie's law. Hysteresis curve. Types of residual magnetization. Origin of the earth's magnetic field. Examples of other planets. Magnetic prospecting (localization and detection). Magnetometers: mechanical, induction, magnetic resonance. Magnetometer comparison with protons and induction magnetometers. Magnetic ground, sea and air reliefs. Diurnal corrections, changes in altitude, regional variations. Notes on Paleomagnetism.
c) Thermal field. Temperature and heat, thermal properties. Temperatures within the Earth. How to measure or assess the Earth's temperature in depth. Transport of heat in the Earth. conduction; convection; radiation; conduction equation. Earth heat sources. Radioactive heat production. Heat transport in the rocks. Earth heat flow. Continental, oceanic, global flow. Thermal models. Thermal structure of the oceanic crust. Mantle thermal structure. Thermal structure of the Core.
Seismology, and seismometry. Elements of physics (elastic waves, amplitude, frequency, period and wave number, Snellius law)
Compositional and rheological structure of the internal structure of the Earth. Background; Historical seismicity and instrumental seismicity. Natural, anthropic and noise seismic sources: characteristics in the frequency domain and over time. Definition of Earthquake. Elastic Rebound theory and seismic cycle. Volume waves (P and S) and surface waves (Rayleigh and Love). The dispersive character of surface waves. Nomenclature of seismic phases within the Earth and the Crust. Location of an earthquake. Hypocentral parameters. Seismic networks. The calculation of the Magnitude. Seismic moment and moment magnitude. Magnitude-Energy Relations. Seismic intensity: most used scales in the world and in Italy. The focal mechanisms. Seismometry: horizontal and vertical seismometers. Seismic sequences, swarm, background seismicity. Outline of seismotectonics and seismic hazard.
