Mercer Ice Stream (84°50′S145°00′W), formerly Ice Stream A, flows west to Gould Coast to the south of Whillans Ice Stream, Antarctica. It is the southernmost of several major ice streams draining from Marie Byrd Land into the Ross Ice Shelf. The ice streams were investigated and mapped by U.S. Antarctic Research Program personnel in a number of field seasons from 1983–84 and named Ice Stream A, B, C, etc., according to their position from south to north. The name was changed by the Advisory Committee on Antarctic Names in 2002 to honor Quaternary geologist John H.