High elevation dye tracing on Khumbu Glacier, Nepal Himalaya

Parameters: Fluorescent Dye Tracing, Fluorescein

In April-May 2018, a group of glaciologists led by PhD student Katie Miles at Aberystwyth University used four PME Cyclops-7 Loggers in combination with fluorescein-detecting Cyclops-7F Submersible Sensors on Khumbu Glacier, Nepal. Khumbu Glacier, whose ice is sourced in the Western Cwm of Mount Everest, flows down the flanks of the mountain from around 7,000 to 4,900 metres above sea level.

The aim of the project was to determine the subsurface drainage system of the glacier, using fluorescent dye tracing. The fluorometers were installed in various outlet streams at the terminus of the glacier, and fluorescein dye injected into streams and ponds further upglacier. The dye return at the fluorometers after each test then allowed the scientists to infer how the water had travelled beneath and within the glacier, from calculations of the transit time, velocity and dispersivity and comparisons between tests.

Sixteen dye trace experiments were conducted in total, over the lowermost 7 km of the glacier. Of these tests, thirteen experiments gave very clear dye returns at the fluorometers, revealing much about the subsurface drainage system. The other three tests were expected to give less clear returns, but still provided useful and previously unknown information about the glacier’s drainage system. Results have been analysed and written up into a paper, which is currently in review for a scientific journal.

Authors: Katie Miles Aberystwyth Unviersity, United Kingdom