Seismology

Specific Foundation / Core

The course is also offered to exchange programme students.

1) Understanding of the basic principles of Seismology 2) Connection of theoretical knowledge with practical exercises 3) Learning the basic principles of seismic wave generation and propagation in the interior of the Earth 4) Learning of the estimation of the basic seismic parameters. 5) Understanding the processes of earthquake generation and their space-time distribution 6) Understanding the methods and the problems of earthquake prediction (short, intermediate and long term) 7) Estimation of seismicity parameters using various methods 8) Understanding the macroseismic effects of the earthquakes on the soil, sea and humans.

1) INTRODUCTION: Main target of the science of Seismology. Research methods in Seismology. Scientific and social importance of Seismology. Short history of Seismology. 2) PRINCIPLES OF ELASTICITY THEORY AND ELASTIC WAVES: Traction vectors at a point, stress tensor, equilibrium conditions, principal stresses, units and values of stress inside the Earth. Strain at a point of a body, normal and shear stresses, rotation, stress-strain relations, elastic constants. Equation of motion, wave equation, equation of vector wave. Elastic body waves: Compressional and shear waves, reflection and refraction of body waves Snell’s low. Surface waves: Rayleigh and Love waves, dispersion of surface waves. 3) INSTRUMENTS OF SEISMIC WAVE RECORDING: Basic principles of seismograph operation, eigen period of a pendulum and ways of changing it, attenuation of a pendulum motion. Theory of seismometers: Equation of motion of the pendulum of a seismometer, response of this motion to the seismic motion. Electromagnetic seismometers and their calibration, digital seismographs and broad-band seismometers. 4) SEISMIC WAVES AND THEIR PROPAGATION INSIDE THE EARTH: Earthquake foci, epicenter, time of origin, travel time curves of seismic body waves, seismic waves velocity versus depth. Seismic wave propagation in the Earth’s crust, mantle and core. Surface wave propagation, free oscillations of the Earth. Attenuation of seismic waves. 5) SEISMOMETRY: Measurement of the arrival time and the period of seismic waves. Fourier spectrum of seismic waves. Particle motion. Travel time curves, estimation of the epicentral distance and the origin time of an earthquake. Estimation of the coordinates of the earthquake foci: Estimation of the epicenter applying the graphical method (travel time differences of P and S waves) using more than two stations, application of the Wadati method for the estimation of the focal depth. Magnitude of an earthquake, different magnitude scales, magnitude saturation, correlation between different magnitude scales. Seismic energy. 6) EARTHQUAKE GENERATION AND THEIR SPACE-TIME DISTRIBUTION: Models of shallow depth and deep focus earthquake generation. Asperity and barrier model of seismic faults. Time distribution of seismicity: The seismic cycle, seismic sequences, accelerating and decelerating seismicity, induced seismicity. Time independent and time dependent seismicity. 7) EARTHQUAKE PREDICTION: Long term earthquake prediction: Seismic cycle for slip and time predictable models, the methods of seismic gaps and static stress (Coulomb stress) change. Intermediate term earthquake prediction: Method od decelerating inside and accelerating outside seismic deformation. Short term earthquake prediction: Earthquake precursors and their physical explanation. Social impact of earthquake prediction. 8) MACROSEISMIC EFFECTS OF EARTQUAKES: Effects on the soil, the water ((Seiches), the sea (tsunamis), and the structures. Effects on the humans and the animals. Estimation of the macro seismic effects, seismic intensity scales, seismic intensity curves. 9) ANTHROPOGENIC QUAKES: Artificial laboratory shock waves. Microseismic noise. Nuclear explosions: energy and magnitude of nuclear explosions, detection of nuclear explosion and their discrimination from earthquakes. Shocks due to chemical explosions. Structure and contain of exercises 1. Seismological instruments and seismological networks (at the Seismological Station site). Instrument response, practice related to the recording of ground motion including spectrum and response curves for each station. 2. Earthquake location and magnitude estimation using the scolv tool. 3. Construction of travel time curves. 4. Seismogram interpretation. 5. Determination of the Vp/Vs ratio using the Wadati method - particle motion. 6. Earthquake location using the graphic method. 7. Estimation of seismicity using the Gutenberg-Richter method. 8. Estimation of seismicity using the Gumbel method. 9. Seismic motion spectrum. 10. Macroseismic effects – Construction of isoseismal map. 11. Study of earthquake sequences (calculation of parameters a, b, spatiotemporal distribution). 12. Retun periods, – Probabilities - Poisson distribution. 13. Revision exercises.

Elasticity, seismic waves, seismic source parameters, seismology, earhquakes, earthquake prediction, macroseismic effects of earthquakes.

10-03-2020