Open AccessSeismic Waves in a Quarter and Three‐Quarter Plane
Author(s) -
Alterman Z. S.,
Loewenthal D.
Publication year - 1970
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1970.tb06058.x
Subject(s) - quarter (canadian coin) , plane (geometry) , explosive material , geology , point (geometry) , geodesy , seismology , motion (physics) , geometry , physics , mathematics , geography , classical mechanics , archaeology
Summary The complete motion of an elastic quarter plane and of a three‐quarter plane with free boundaries caused by an explosive point source, is obtained by finite difference methods. Varying ratio β/α of the shear to compressional wave velocity shows that in the quarter plane the amplitude of motion at the corner increases with increasing β/α, in the three‐quarter plane it decreases. The motion in the quarter plane differs from the sum of reflections at perpendicular half planes. The amplitude of diffracted P waves varies mainly with distance from the corner. The amplitude of diffracted S waves varies mainly in angular direction. Corner‐generated surface waves and elliptical particle motion in the waves are analysed. At the corner of a quarter plane, the amplitude of the Rayleigh wave is three to five times as large as on a half plane, the particle motion is elliptic and the major axes of the ellipses are inclined at 45° to the free surface.