Groundwater Action Group

Groundwater is a physical link between a series of key Antarctic climate, environmental and biological processes.  Although difficult to observe, there is evidence that groundwater plays a significant role in the global water budget, ice-sheet dynamics, ecosystem function, and carbon and methane cycling:

• Potential storage of liquid-water within continental Antarctica is equivalent to 0.1-1 m of global sea level rise.
• Groundwater and subglacial water ‘lubricate’ ice sheets, accelerate ice discharge to the ocean, and enhance basal melting of ice sheets. Recent research highlights influence of groundwater on heat-flow and ice-dynamic processes, with potential for global impact though non-linear rates of sea level rise.
• Groundwater globally is known to host microbial ecosystems that enhance weathering reactions, contributing solutes to the fluids; the very limited sampling of presumed groundwaters from Antarctica indicate these waters are also solute-rich and host active microbial communities. Little is known about the diversity and function of this potentially continental-wide ecosystem.
• The presence of liquid water has a profound impact on life in Antarctica. Discharge of groundwater both on land and offshore is highly relevant for biology and ecosystems, as any changes to liquid water availability will drive ecosystem changes.  Significant volumes of water and dissolved gases have been discovered within the continental landmass – with evidence for their discharge into the coastal margins.  The discharge of groundwater, particularly waters high in nutrients, gases, acidity and/or salinity can cause dramatic changes to ecology.
• Long distance transfer of nutrients – Despite the cold temperatures and very few rivers traversing the exposed coastal plain and dry valleys, recent research implies much longer distance transport via groundwater moving nutrients from beneath Antarctica’s ice sheets out to coastal terrestrial and marine environments supporting a range of unique life.
• Unquantified volumes of water and gases, among which are carbon dioxide and methane, exist in shallow reservoirs in the Antarctic ice and permafrost, which are sensitive to climate change given their relatively shallow depth. Their release, through flow of subsurface water could dramatically affect the emissions of greenhouse gases.

Despite the apparent importance of groundwater, many concepts are still hypothetical, scientific and public awareness is low, underpinning data to constrain the extent and influence of groundwater-systems is lacking.  Volumes of Antarctic groundwater have yet to be considered in global inventories, knowledge of occurrence and flow is limited, and offshore flux is essentially unknown.

Aims, Goals and Objectives

Here we propose an Action Group Groundwater to improve understanding of the flux and flow of liquid-water through the continental rock-mass and its interaction with, and influence on, the cryosphere and biosphere. Specific objectives are:

• Bring the international communities together to address this cross-disciplinary and wider continental margin topic and solicit wide international representation.
• Produce an Antarctic state of the environment whitepaper with regards to groundwater, which:
  • Compiles subsurface hydraulic and hydrogeological properties in an open (GIS) data structure.
  • Compiles models across disciplines through workshops that explore requirements to link models per discipline, including need for observed data.
  • Recommendations for targeted research, logistics and building partnerships through SCAR science priorities.
• Seek feedback from Science Groups and Research Programmes.
• Facilitate exchanges of early career and other scientists with an interest in cross-disciplinary spatial representation and/or modelling.