Onyx River

Onyx River
Onyx River flowing into Lake Vanda
Overview map

The Onyx River is a meltwater stream which flows westward through the Wright Valley from Wright Lower Glacier and Lake Brownworth at the foot of the glacier to Lake Vanda, during a few months of the Antarctic summer.

The Onyx River is one of the many sites studied by the United States Antarctic Program of the National Science Foundation. The river flow is away from the ocean as the Wright Glacier blocks the entrance to the valley. It is the largest river in Antarctica and, at 25 miles (40 km) in length, it is also the longest. It has several tributaries, and there are multiple meteorological stations along the length of the river. Flow levels are highly variable, both during the day and between summers, with the river failing to reach the lake some years. In contrast, it can cause significant erosion in flood years, and was rafted in 1984 by New Zealand researchers. While there are no fish in Onyx River, it does support microscopic life, and the algal blooms can be quite extensive. The Antarctica New Zealand program once maintained a semi-permanent camp at Lake Vanda which has since been removed. Currently there is a small research shelter at Lake Vanda at its eastern end. Nearby is the Comprehensive Test Ban Treaty Seismic station at Bull Pass.

Map of Wright Valley with Onyx River and Lake Vanda


References

  • "Antarctica’s longest river", p 16, and "What the flood revealed", pp 15–21, Antarctic Sun, January 26, 2003

Coordinates: 77°32′00″S 161°34′01″E / 77.5333°S 161.567°E / -77.5333; 161.567


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