Localized Temporal Change of the Earth's Inner Core Boundary
Lianxing Wen
Compressional waves of an earthquake doublet (two events occurring
in the South Sandwich Islands on 1 December 1993 and 6 September
2003), recorded at three seismic stations in Russia and Kyrgyzstan
and reflected off Earth's inner core boundary, arrived at least
from 39 to 70 milliseconds earlier in the 2003 event than in
the 1993 event. Such changes indicate that Earth's inner core
radius enlarged locally beneath middle Africa by 0.98 to 1.75
kilometers between the times of these two events. Changes of
the inner core radius may be explained by either a differential
motion of the inner core, assuming that irregularities are present
at the inner core boundary and fixed to the inner core, or a
rapid growth of the inner core by this amount.
E-mail: Lianxing.Wen{at}sunysb.edu
