AbstractVolcanic activity on sub‐Antarctic Marion Island is found to have occurred only during the interglacials. The present volcano distribution is associated with a radial and peripheral fault system, the location of which appears to be related to the former glacier distribution. An hypothesis is presented suggesting that the faulting is a result of deglaciation and that the specific location of the faults is due to the differential stresses occurring between ice‐covered and ice‐free areas during isostatic uplift. The faulting initiates volcanism due to the location of the island within a volcanic r