Syllabus
History of the investigation of seimic rotational motions discussion of possible rotational motion manifestation on certain structures for present- time and historical earthquakes
Basics of the theory of elasticity and curl of seismic wave field tensor of small rotations, curl of seismic displacement field, influence of the earth‘s surface
Numerical modeling of seismic rotations in simple structures wavefields simulations in homogeneous or gradient media for a double couple or center of rotation point source
Ring laser measurements of seismic rotation basic principle, examples of rotational seismograms
Determination of seismic rotation from small-aperture arrays
ADR (Array Derived Rotation) method, basic principle, conditions of applicability, accuracy estimates
Direct measurements of seismic rotation by point sensors new types of rotational sensors and basic measurement principles, Rotafon - a six- degree-of-freedom seismic sensor (patent FMP CU), in-situ calibration
Generator of seismic rotational motions repeatable source generating SH waves and rotational motions, signal stacking, linear and non-linear summing method
Rotational seismograms and matching the rotation and translation waveforms waveform analogy between rotation rate and translational velocity, quantification of rotational amplitudes by the Rotation-to-Translation-Ratio (RTR), frequency dependence of RTR, RTR depencence on other parameters
Structural effects in rotation seismic wavefield phase velocity determination
Source effects in rotation seismic wavefield determination of focal mechanism
Annotation
Rotational seismology is a new developing seismological discipline which, in contrast to classical approach based on measuring of translational motions, deals with rotational ground motions. Main topics of the lecture are: history of the investigation of rotational components, basics of the theory of elasticity and curl of seismic wave field, numerical modeling of seismic rotations in simple structures, measurements of seismic rotations, generating of rotations by an anthropogenic source, rotational seismograms and matching the rotation and translation waveforms, structural and source effects.