Iceberg patterns refer to a particular part of the flesh-point coordinate time function of a crucial articulator for an obstruent gesture [O. Fujimura and W. Spencer, J. Acoust. Soc. Am. Suppl. 1 76, S59 (1983)]. They were found stable for a given demisyllable in different prosodic contexts, when a microbeam pellet height value, around which the time function was excised for comparison, was optimally selected. The time for crossing such a selected threshold height was found useful for studying phonetic phrasing patterns. The C/D model [O. Fujimura, J. Acoust. Soc. Jpn. (E) 13, 39–48 (1992); O. Fujimura, Proc. ICPhS 3, 10–17 (1995)] proposes that the articulatory control function is composed of impulse response functions (IRFs) for elemental gestures, which are magnified according to the syllable strength. Therefore, the movement velocity at a given time relative to the syllable pulse (i.e., in a given phase of transition) will vary according to the syllable magnitude. The two approximation principles will be shown to be mutually consistent when the saturation effects of the physical articulatory system is considered along with general properties of the IRFs for obstruent gestures. [Work supported in part by research and education funds provided by ATR/ITL and ATR/HIP.]