The atomic force microscope is used to explore the nature of fracture surfaces in soda lime silicate glass formed near or below the apparent crack growth threshold. Conventional theory suggests that cracks in glass will blunt when subjected to stresses below the threshold. We see no blunting in this study. Cracks that are held below the apparent crack growth threshold for 16 h alter their mode of growth. The fracture plane changes from a flat surface to a surface that exhibits substantial out of plane growth. The crack changes its growth direction to an angle that lies between 3 and 5 to the original growth plane, leaving behind a wavy fracture surface. This change crack morphology is believed to cause a time delay to restart crack motion when the applied stress intensity factor is again raised above the apparent crack growth threshold.