IGF



Geophysical Laboratory I/II, academic year 2017/2018

Academic year: 2017/2018
Semester: winter

LECTURE DESCRIPTION

Courses materials

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Lectures / Leader Lecture type

The task will be to determine the three models of the Earth's crust: oceanic area and the continental platform and cratons. As part of the introduction to the exercise will be presented the basics of propagation of elastic waves in multilayer medium and simple program for calculating travel-time in 1D structure (program HOD with graphic support PLOT). The data for modelling will be seismic sections (collections of seismograms ) obtained from seismic experiments. The task will be to extract waves in these sections, and then fit the three models of the velocity distribution of longitudinal waves for seismic section of the Atlantic Ocean, SW Polish and Baltic Shield. The summary task will be to compare models and comment on the differences in the crustal structure of the three different tectonic areas.

Lecturer: Prof. Marek Grad (mgrad@mimuw.edu.pl)

Class

On the basis of several seismograms should be set the time and place of the earthquake. It will be a case of " close " earthquake allow some simplification. As part of the introduction to the exercise, will be presented the basics of propagation of longitudinal (P) and shear (S) seismic waves, and the method of Wadati spheres to obtain an earthquake location. The task will be to identify the P and S waves on seismograms, to pick their onset time, to determine a time t0, and to locate an earthquake for the known geometry of positions of seismic stations. Base variant will be based on synthetic data ("no errors") gives the possibility to verify the result with the known location of the source. Extended variant will be based on actual recorded data of an earthquake from seismic catalog. In this case, the comparison will be done with the catalog information, obtained as a result of routine seismological studies by professionals. In both variants a person performing the exercise will have an invention to analyze the errors of calculation of time of the earthquake, the epicenter and the depth of the source.

Lecturer: Prof. Marek Grad (mgrad@mimuw.edu.pl)

Class