  Sunquakes are the surface signatures of acoustic waves in the Sun's interior
that are produced by some but not all flares and coronal mass ejections (CMEs).
This paper explores a mechanism for sunquake generation by the magnetic field
changes that occur during flares and CMEs, using MHD simulations with a
semiempirical FAL-C atmosphere to demonstrate the generation of acoustic waves
in the interior in response to changing magnetic tilt in the corona. We find
that Alfven-sound resonance combined with the ponderomotive force produces
acoustic waves in the interior with sufficient energy to match sunquake
observations when the magnetic field angle changes by the order of 10 degrees
in a region where the coronal field strength is a few hundred gauss or more.
The most energetic sunquakes are produced when the coronal field is strong,
while the variation of magnetic field strength with height and the time scale
of the tilt change are of secondary importance.
