Significance of non-double couple components
of deep and intermediate-depth earthquakes: implication from moment tensor
inversions of various long-period seismic waves,
Kuge, K., and H. Kawakatsu
Phys. Earth Planet. Int., 75,
243-266, 1993.
Abstract
Analysis of moment tensor inversions
of various long-period seismic waves
suggests that
non-double couple components of
intermediate-depth and deep earthquakes
really exist in the source moment tensors and
appear to respond to the state of predominant strain release within slabs,
partially or fully
caused by sources themselves or slab structures near the sources.
We observe consistency in the non-double couple components
from three different inversions of different seismic waves:
Among 21 non-double couple earthquakes that we studied,
16 events show the same sign in the
three non-double couple components, and the signs have a correlation with
the state of strain release within the slabs.
The propagation effects of unmodeled structure
and instability in the inversion procedure
are unlikely to be responsible for
the consistent non-double couple components
because different seismic waves traverse different paths and different
inversion schemes are performed under the different resolvability.