Ora, questo emerito sig. Stephen H. Kirby dell'USGS si espone pubblicamente con una dichiarazione di questo tipo:
Earthquake mechanisms based on frictional instabilities are widely accepted for relatively shallow earthquakes. Such mechanisms, in unmodified form, are highly unlikely for deep earthquakes because of the expected high frictional shear stresses at depths of 300–700 km.
e conclude con:
Finally, if this is the earthquake source mechanism in deeply subducted lithosphere, then earthquakes should shut off when all of the polymorphic phase changes have occurred. This may explain the maximum depth of earthquakes at about 680 km.
dopo aver fatto dei test con i suoi colleghi.
federico_forlì ha espresso un suo parere, avrei piacere a sentirne anche degli altri.
Grazie
