The concept of directed resonance is put forward, and its occurrence in New Zealand and overseas is documented. It is observed mainly on water-saturated recent alluvium. Analytical procedures for detecting directed resonance effects in earthquake records are outlined. The resonance parameters are shown to be independent of the particular earthquake, and highly dependent on local boundaries of the alluvium. Cellular mode resonant response is suggested to be the mechanism generating directed resonance at individual sites, and is shown to occur for scale models of alluvial deposits. Experimental apparatus which would be needed to unequivocally confirm the earthquake excitation of cellular resonant modes is described in an appendix.