Dynamical oscillations and glitches in anomalous X-ray pulsars

Recently reported observations of magnetar glitches and coincident X-ray long-term brightening events establish enough of a database to indicate that the brightening events are accompanied by glitches at their outset, and that they are probably triggered by the same event that triggers the glitch. We suggest, on the basis of various observational clues, that (1) these are caused by energy releases at depths below 100 m and (2) the unpinning is due to global mechanical motion triggered by the energy release, not by heat. Because mechanical triggering of a glitch requires less energy than a detectable long-term X-ray brightening, the latter does not necessarily accompany every glitch, but it is predicted, when it does occur, to be heralded by a glitch. Crustal oscillation associated with the mechanical energy release may cause short (≪10³ s) flares.