Ice flow of Humboldt, Petermann and Ryder Gletscher, northern Greenland

This is the published version. Copyright 1999 International Glaciological SocietyRadar interferometry, ice-penetrating radar profiles and an elevation model are used to determinc the veloeity fields, rates of ice discharge, approximate states of balance and catchment area for three large outlet glaciers in northeast Greenland. Discharge through flux gates is calculated for Humboldt and Petermann Gletscher, which are found to be in balance (at the level that the accumulation is known). A large diflerence between the measured and estimated fluxes for Ryder Gletscher may be a reflection of unsteady flow behavior for this glacier. The patterns of ice flow for the threc glaciers considered are each unique, showing that the nature of ice discharge varies substantially from basin to basin, controlled by bed conditions and the presence of subglacial troughs and obstructions