Open AccessEffects of Major Seismic Events on the Rotation of the Earth
Author(s) -
BenMenahem Ari,
Israel Mashe
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.tb06054.x
Subject(s) - geology , earth's rotation , polar motion , azimuth , geodesy , seismology , magnitude (astronomy) , rotation (mathematics) , secular variation , latitude , geophysics , polar , seismic wave , geometry , physics , mathematics , astronomy
Summary A spherical theory is advanced for perturbations of the Earth's rotation by major earthquakes and explosions. Explicit expressions are obtained for the dependence of the secular polar shift on the dimensions, depth, and location of the seismic event. Numerical results show that a single shallow earthquake of magnitude 8.5, occurring at a suitable latitude and with a favourable strike‐azimuth, may suffice to maintain the Chandler wobble for about one year. Hence, it is deduced that earthquakes may at most account for 30 per cent of the observed secular polar shift.