Maps of badpass-filtered geoid height anomalies deduced from Seasat altimetry data - which are referred to as ''geoid roughness maps'' - are contoured over the Indian Ocean both in the short (30-90 km) bandwidth and in an intermediate one (90-230 km). Interpretation of these maps essentially provides a guide as to where further detailed studies should be conducted. The roughness maps can thus be used as a fast and efficient ''scanner'' for isostatic processes at the scale of an entire ocean. Additionally, roughness maps provide a qualitative appraisal of the emplacement mechanisms of intraplate features: this can for example be appreciated by comparing the interpretations of the maps with the results of admittance studies over such features. ¿American Geophysical Union 1990