A new compilation of bathymetric surveys surrounding Heard Island, near 53°00' S, 73°30' E, appears to show geomorphic evidence that the island and surrounding submarine plateau were covered by a 100-km-wide tidewater ice cap at some time in the past. If this ice cap existed, it presumably did so at the last glacial maximum when relative sea level was lower than present. Even so, it would have been grounded in at least 180 m of water and therefore must have been several hundred meters thick.