Geometry and flow conditions of subglacial water at South Cascade Glacier, Washington State, USA; an analysis of tracer injections

Tracers were injected into South Cascade Glacier to determine the flow condition and geometry of the subglacial water system. Results indicate that two distinct drainage basins on the glacier feed the two main streams flowing from the glacier. In the largest basin, two parallel drainage networks exist, one englacial and the other subglacial. The englacial system is an arboresecent network of conduits, whereas the subglacial system is a distributed flow system. Both systems connect to a single subglacial conduit which appears as a stream at the glacier’s terminus. The comparison between the travel time of the tracers and stream discharge indicated that the single conduit was pressurized in July and partly filled in August and September.