VICTOR RAILEANU, DORU MATEICIUC, ALEXANDRU POMPILIAN
Institutul National pentru Fizica Pamantului Bucuresti – Magurele
POLARIZATION OF SEISMIC WAVES RECORDED ON A PROFILE FROM NORTH DOBRUDJA
(Abstract)
The polarization of seismic waves recorded on a refraction seismic line is
analyzed.
The P and S first arrival analyzed on 3 components show, on the particle motion
diagrams, the azimuths and pseudo-dip of the emergent waves.
Some seismic energy diagrams of the horizontal components on the time windows
around the S-wave reflections from the Conrad and Moho display an energy concentration
along of two orthogonal directions: NW-SE and NE-SW. These are the polarization
directions of the splitted seismic shear waves as a result of the propagation
through an anisotropic medium, that is, a medium having a system of fluid-filled
microcracks. The anysotropy could have regional or local causes: a horizontal
tectonic stress or a stress field around the fractures align on the NW-SE direction.
Key words: North Dobruja, anisotropy, shear wave polarization, shear wave splitting.