An Ablation Rate for Lake Fryxell, Victoria Land, Antarctica

Abstract

The average yearly net ablation rate on permanently ice-covered Lake Fryxell, Victoria Land, Antarctica, is 30 to 40 cm. This figure was calculated by a novel method utilizing a record of ablation which is incorporated in the ice cover of the lake. These values are higher than those measured on Ross Island 80 km. to the east; the difference in ablation rates for the two areas is attributed to the prevalence of katabatic winds in the climate of Taylor Valley. The Lake Fryxell ablation figure is applied to nearby Canada and Commonwealth Glaciers in the calculation of their ice budgets.

Effects of glacial meltwater inflows and moat freezing on mixing in an ice‐covered antarctic lake as interpreted from stable isotope and tritium distributions

“…Since 197 1 the surface level of the lake has increased an average 10.5 cm yr-l, although some yearly decreases in elevation were also measured (Chinn 1993). Surface-ice ablation determined in Lake Fryxell (30-40 cm yr-I, Henderson et al 1965) is similar in nearby Lake Vanda and Lake Hoare (2) yielding a whole-lake residence time of 22 yr. This is a maximum residence time because evaporation of water from the moat is not included and because we chose the lower estimate for ablation.…”

“…The combined sources of water maintain a positive water balance in the lake, as seen by a 2-m rise in lake level since 197 1 (Chinn 198 1, 1993). Surface-ice ablation is the main water loss (30-40 cm yr-l; Henderson et al 1965). The ice-cover thickness of Lake Fryxell has varied little over time, ranging from 4.0 kO.5 m in 1963 and 1987-l 99 1 (Hoare et al 1965; this study) to a minimum of 3.5a0.5 m in 1986 (Clow et al 1988), suggesting that at present, freezing and ablation are in balance, but the water budget is not in hydrologic steady state because inputs exceed ablation plus moat evaporation.…”

Sediment Melt-Migration Dynamics in Perennial Antarctic Lake Ice

“…7). Because the surrounding ice also ablated at an estimated rate of 0.1 cm day 21 (Henderson et al, 1966;Clow et al, 1988), the absolute velocity of the sediment patch was about 1.3 cm day…”

“…At the same time, air temperatures must allow for a balance between the accretion of new (bottom) ice and the ablation of old (surface) ice. The ablation rate of the Lake Fryxell ice cover varies considerably because of summertime melt and the dry katabatic winds which are most frequent during non-summer months (Henderson et al, 1966;Doran et al, 2002b (Clow et al, 1988). Much higher ablation rates, up to ,1.5 m yr…”

“…Intraseasonal variation in surface ablation was also noted at Lake Hoare by Clow et al (1988) and is likely associated with summertime melting at the ice surface. The ice cover thickness of Lake Fryxell ranged from 3.8 to 4.5 m between 1961 and 1963 (Henderson et al, 1966), and from 3.5 to 6.0 m between 1995 and 2006 (Priscu, unpublished data; MCM LTER).…”