PKJKP
The Earth’s inner core was discovered more than 65 years ago. The ultimate proof that the innermost Earth is solid would be shear waves traversing the inner core, but for many years subsequently there were no reliable observations of such waves. As an undergraduate at Utrecht University in the Netherlands, I made the first observations of inner core shear waves by comparing the data with synthetic seismograms for earth models having either a solid or fluid inner core. This observation solved an important issue remaining from the early years of seismology.
Observation of an inner core shear wave (pPKJKP and SKJKP) for the deep Flores Sea event of 17 June 1996. The shear wave arrival is present in synthetics calculations for a solid inner core, but disappears for a model with a fluid inner core. Such tests are essential to make unequivocal observations of inner core shear waves. From Deuss et al. (2000).
Key publications
- Deuss, A., Woodhouse, J. H., Paulssen, H, and Trampert, J. (2000). The observation of inner core shear waves, Geophysical Journal International 142 (1), p.67-73