History of Taylor Valley
Taylor Valley has been the site of extensive glaciation and deglaciation
during the past 20,000 years, which has strongly affected lake water
levels in the valley over time (Hall et al. 2000, Lawrence and Hendy
1989, Myers et al. 2021). Ice from the Ross Ice Shelf advanced into the
valley during the Last Glacial Maximum (LGM) (28.5-12.8 years BP) when
local air temperatures were 4-9 °C lower than modern (Steig et al.
2000). Ice sheet advance resulted in an ice dam at the mouth of Taylor
Valley which reached elevations up to 300-350 meters above sea level
(m.a.s.l.) and allowed the formation of a large paleolake, Glacial Lake
Washburn (GLW), which filled all of Taylor Valley (Hall and Denton 2000,
Lawrence and Hendy 1989, Myers et al. 2021). Lake levels in Taylor
Valley have undergone drastic changes since the LGM; post-LGM ice dam
retreat caused drainage of GLW and lowered lake levels to approximately
81 m.a.s.l. (Levy et al. 2017, Myers et al. 2021). Lake levels fell
further as drainage into the Ross Sea continued, and high rates of
evaporation likely resulted in the formation of a shallow brine pond in
the Fryxell basin around 1000 years BP (Lawrence and Hendy 1989, Levy et
al. 2017). Lake basins subsequently refilled with glacial melt waters,
and lake levels have been rising since observations began during Robert
Scott’s first expedition in 1903 (Doran and Gooseff 2022, Myers et al.
2021, Scott 1905).