  Glitches are commonly observed for pulsars, which are explained by various
mechanisms. One hypothesis attributes the glitch effect to the instantaneous
moment of inertia change of the whole star caused by a starquake, which is
similar to earthquakes caused by fast dislocation occurring on planar faults
for the static stress, though the quake-induced dynamics responsible for glitch
(superfluid vortex vs. pure starquake) remains still unknown. However, a
theoretical model to quantitatively explain the stress loading, types of
starquakes, and co-seismic change of moment of inertia is rarely discussed. In
this study, we incorporate elastic deformation theories of earthquakes into the
starquake problems. We compute the field of stress loading associated with
rotation deceleration and determine the optimal type of starquakes at various
locations. Two types of pulsar structure models, i.e. neutron and strangeon
star models, are included in the computation and their differences are notable.
Our calculation shows that the observed glitch amplitude can be explained by
the starquakes in the strangeon star model, though the required scaled
starquake magnitude is much larger than that occurred on the Earth. We further
discuss the possibility to compute the energy budget and other glitch phenomena
using the starquake model in the elastic medium framework.
