IEDA
Project Information
Formation and Characteristics of Brine-rich Water in the Dry Valleys, Antarctica
Short Title:
Brine-rich water Dry Valleys, Antarctica
Start Date:
2017-08-15
End Date:
2020-07-31
Project Location(s)
Don Juan Pond
Wright Valley
Dry Valleys
Description/Abstract
This study aims to better understand salt accumulation in cold deserts and develop a model of salt transport by groundwater. Cold deserts, like the Antarctic McMurdo Dry Valleys (MDV), are similar to hot deserts in that they accumulate high concentrations of salts because there is not enough water to flush the salts out of the soils into the ocean. The accumulation of salt allows for the creation of brine-rich groundwater that freezes at much lower temperatures. Field work will focus on several groundwater features in the MDV including Don Juan Pond, a shallow lake that accumulates extremely high levels of salts and does not freeze until the temperature reaches -51 degrees C (-60 degrees F). The setting offers the potential to better understand this unique water environment including life at its extremes. It also serves as an analog environment for Mars, a planet that is entirely underlain by permafrost, similar to the MDV. This project will support a doctoral student at the University of Washington Department of Earth and Space Sciences, who will be trained in chemical analysis, chemical and physical modeling, and remote field work in a polar desert environment.

Past research suggests that the movement of soluble ions in sediment and soil is controlled by the water activity, permeability, and the thermal regime; however, processes controlling the ionic redistribution in Antarctic environments are poorly constrained. This project aims to better understand the formation, salt redistribution, and water activity of pervasive brine-rich groundwater that is enriched in calcium chloride. A primary goal is to develop a brine thermal;reactive;transport model for the MDV region using data collected from the field to constrain model inputs and ground-truth model outputs. The model will develop a Pitzer-type thermodynamic, reactive transport model and couple it to a ground temperature model. The model will test mechanisms of groundwater formation in the MDV and the properties (e.g. composition, temperature, and water activity) of widespread shallow brine-rich waters. Water is an essential ingredient for life and defining processes that control the availability of water is critical for understanding the habitability of extreme environments, including Mars.
Personnel
Person Role
Sletten, Ronald S. Investigator and contact
Funding
Antarctic Earth Sciences Award # 1643550
AMD - DIF Record(s)
Deployment
Deployment Type
Don Juan Pond, Dry Valleys, 2017-2018 field camp
Data Management Plan
None in the Database
Publications
  1. Toner, J. D., D. C. Catling and R. S. Sletten (2017). "The geochemistry of Don Juan Pond: Evidence for a deep groundwater flow system in Wright Valley, Antarctica." Earth and Planetary Science Letters 474: 190-197. (doi:10.1016/j.epsl.2017.06.039)