Hi Chris:

>Because of temperature-pressure conditions that >you discuss, I believe that most deep >earthquakes are considered to occur within the >stronger slab.

At nearly 700 kms depth, according to current theory, there's no such thing as a "Strong slab" since the rock is ductile anyway (whether part of a slab or not). NO brittle failure is possible at these depths (per current theory).

I appreciate the attempt at steering around the problem by saying that somehow the slab retains some type of advantage in strength. ==>This may be true but conflicts with the pressure-depth assumptions of current theory...which says that anything below about 70 kms is ductile and "flows" thus pre-empting shearing (and cavities) and brittle failure.

Good update on the Carpathians, etc.

Maybe seismic wave timing and related assumptions should be re-visited as one area of investigation to resolve the mystery....

$.02