Taku Glacier, an advancing former tidewater glacier in Alaska, has been actively pushing its proglacial sediments along part of its terminus over the last 50 years, producing so-called push moraines. The mobilization of these sediments, which were locally lifted more than 20 m above sea level by 2004, has happened episodically rather than steadily. The last major event of proglacial sediment deformation occurred in 2001, presumably caused by sliding along a basal detachment layer. Since then, most deformation has been localized within a few meters of the terminus, including impressive deformational features of the terminal ice, where slabs of ice, tens of centimeters in thickness, have undercut proglacial sediments and vegetation and lifted them up. Between 2002 and 2004, surface velocities and horizontal displacements were measured across the terminus and in the proglacial push moraine area. Sediment displacement was highest between the end of March and mid-June. A decrease in displacement with distance from the terminus revealed that the sediments were deforming internally rather than along a basal d¿collement. We present a simple model which suggests that, under 2004 conditions, reactivation of major movement along this d¿collement is unlikely to happen, unless some critical factors change. These factors include (1) a steepening of the glacier surface, (2) an increased surface angle of the sediment wedge, and/or (3) higher water pressure in the system, which decreases the effective frictional resistance. An observed wet clay-rich layer presumably acted as a major fault plane during the 2001 event.