McMurdo Dry Valleys Lake Descriptions

Detailed physical descriptions of lakes found in the McMurdo Dry Valleys. Lake Fryxell basin is formed by a moraine depression in a wider portion of the Taylor Valley. It has a number of moraine islands and shallower areas, as well as several relatively well developed deltas. The lake is fed by at least 10 meltwater streams with a total drainage catchment of 230 km2. The lake is dammed to the southwest by the Canada Glacier and is topographically closed. It is perennially ice covered; during summer months, an ice-free moat generally forms around much of the lake margin. Lake levels have risen ~2 m between 1971 and 1996. There are no surface outflows; the only known water loss is through ice ablation (evaporation, sublimation and physical scouring). Lake elevation: 18 m. Maximum depth: 20 m. Lake Hoare occupies a narrower portion of the Taylor Valley, dammed by the Canada Glacier. It would drain almost completely without this dam. There are a number of islands which may be related to an old terminal of Canada Glacier. The lake is fed primarily from direct runoff from the glacier, as well as meltwater streams. (Lake level rose ~1.5 m between 1972 and 1996). There are no surface outflows; the only known water loss is through ice ablation (evaporation, sublimation and physical scouring). Lake elevation: 73 m. Maximum depth: 34 m. Lake Vanda is located in the Wright Valley, adjacent to the Taylor Valley. It is fed primarily by the Onyx River, which has its origin at Lake Brownworth, and ultimately at the Lower Wright Glacier located ~27 km east of the lake. The lake has no outflow. Lake elevation: 143 m. Maximum depth: 75 m. Pony Lake on Ross Island is located on Cape Royds. It is a shallow pond ~120 m long, 70 m wide, and 1-2 m deep. Huts built by Shakleton's expedition of 1908 face the southern end of the pond. The eastern shore of Pony Lake is adjacent to a penguin rookery and the pond has high nutrient concentrations. High levels of Na, Cl, and SO4 are probably due t