Recently, new data have been acquired on the chemical composition of waters within the glacial till beneath the Kamb Ice Stream (KIS, formerly Ice Stream C) and the Bindschadler Ice Stream (BIS, formerly Ice Stream D), two of the arteries of ice loss from the Antarctic Ice Sheet (AIS). We compare this water chemistry with basally stored subglacial waters from Arctic and Alpine glaciers and the only other measurements of sub-ice sheet chemistry to date, that emerging from beneath Law Dome near Casey Station, SW Antarctica, during a jökulhlaup. We find that the chemistries pose significant questions about the hydrology and biogeochemistry of ice sheet beds. Copyright © 2010 John Wiley & Sons, Ltd.