Taylor Valley Lakes

Oxygen stable isotopes and chloride concentration in the

surface waters of Taylor Valley Lakes, Antarctica, during the

past 40 years

Julie M. Brown*, W. B. Lyons*, K. A. Welch*, P. Doran, C. B. Dowling, D. M. McKnight,

and J. C. Priscu*The Ohio State UniversitySchool of Earth Sciences

4 November 2012

Taylor Valley Lakes

162°

163°

77°4

5’

77°3

5’

• Geography

• Hydrology & meteorology

Lake Bonney

Lake Hoare

Lake

Fryxell

Andersen

Creek

Taylor Valley Lake Levels

Figure courtesy of Peter Doran, Univ. Illinois, Chicago

Year

Ch

an

ge

in la

ke

de

pth

sin

ce

Jan

ua

ry 1

972

(m

ete

rs)

’72 – ‘91

’92 – ’01*

‘02 – ‘11

* Flood year

lake level lake level

Data courtesy of Peter Doran, Univ. Illinois, Chicago

lake level lake level

Taylor Valley lakes water isotope vs. depth work

• Matsubaya et al. (1979)

• Lyons et al. (1999)

• Gooseff et al. (2006)

• 2005-2006 season courtesy of Carolyn Dowling, Ball State University

• 2011-2012 season with the aid of the MCM-LTER group “Limno Team”

Photo courtesy of A. Chiuchiolo

Annual/decadal variations in salinityand δ18O of lake surface waters

’72 – ’91: lake levels

’92 – ’02: lake levels

‘03 – ‘11: lake levels

Map

-33.7‰

-31.2‰

-29.5‰

N

Canada GlacierLakeHoare(δ18O -35.9‰ to -32.4‰)

Historical δ18O Canada Glacier ice and melt regimes to

Lake Hoare

Oxygen isotope data compiled by D. Leslie, Ohio State

Andersen Creek

December and January

Lake Hoare surface waters-35.9‰ to -32.4‰

Andersen Creek-31.2‰ to -28.4‰*

freezing (February - November)

lake ice+3‰ enrichment**

Canada Glacier

** O’Neil (1968)

glacier snow and ice

-33.7‰ to -29.5‰

Lake Hoare basin δ18O

* Anderson Creek data from 2010 and from personal communication with D. Leslie, Ohio State

Conclusions

• The Taylor Valley lake surface waters vary with time isotopically– Heterogeneous glacier ice – Degree of variability depends on hydrology– Isotopic fractionation processes vary with

climate

• Lake Hoare surface waters are getting isotopically lighter during last 5-6 years– Significant melting of the foot of Canada Glacier

relative to Andersen Creek water

Future work• Continued annual (and seasonal) collection

of lake water column isotope data

• More spatial Taylor Valley glacier ice isotope samples

• Model isotope data of streams, glaciers, and lakes (and lake ice)

Acknowledgements• This work was supported by NSF Grant

OPPP-ANT-1115245

• MCM-LTER project

• Dr. W. Berry Lyons, Kathleen Welch, Deborah Leslie, Christopher Gardner, ‘11-‘12 MCM-LTER “Limno Team”