Antarctic surface hydrology and impacts on ice-sheet mass balance - Bell et al 2018

Flashcards about antarctic hydrology and ice sheet mass balance

What is the importance of projecting future sea-level rise for coastal communities?

It is essential for coastal communities around the globe.

What are the major components of the Antarctic surface hydrology system?

Surface water is found in supraglacial lakes, subsurface lakes, surface streams, and rivers.

How is the surface melt distribution in Antarctica determined?

Using satellite observations and reanalysis-forced regional climate modeling

Where is the most intense melt observed in Antarctica?

Across ice shelves, particularly along the Antarctic Peninsula and low-latitude East Antarctic ice shelves

What is the typical upper elevation limit of surface melting in West Antarctica?

Generally ~1,400 m

What role do surface fractures (crevasses) play in Antarctic hydrology?

They accumulate water and serve as a mechanism by which water directly impacts ice dynamics.

Where do lakes on grounded ice typically develop?

In areas with local-scale melt enhancement and relatively low accumulation rates

What controls the surface depressions in ice shelves where water collects?

Basal crevassing, grounding zone flow-stripe development, suture-zone depressions, and basal channels produced by ocean melting

What is the impact of water collecting in ice shelf depressions?

The basin will deepen due to both enhanced lake-bottom ablation and the flexural response of the floating ice to the water load

What happens when meltwater from surface lakes freezes over and is buried by snowfall?

Antarctic surface meltwater is stored englacially.

What is the capability of radar satellites like C-Band Sentinel-1 A and B?

capable of penetrating metres though dry snow, highlighting the promise of tracing buried lakes and other subsurface liquid water

What are the consequences of refreezing lakes?

They form massive ice layers.

Where do drainage systems often terminate in Antarctica?

Where they deliver water into snow-covered areas

How does meltwater transport occur across Antarctica?

Along relatively low surface slopes through networks of streams and rivers

What role do streams and rivers play in ice-sheet mass balance?

By moving water onto ice shelves where ponding water can contribute to ice-shelf collapse

What is the role of transporting meltwater off floating ice shelves?

Has the potential to buffer ice shelves from fracture and collapse associated with surface lakes

What drives Antarctic surface meltwater distribution?

Regional shifts in climate together with the influence of local-scale processes and microclimates

How can local-scale process enhance melting?

Exposure of low-albedo blue ice and bedrock near ice-shelf grounding zones.

What role do winds play in surface meltwater production across Antarctica?

enhancing surface melting across ice-shelf grounding zones, and contribute to melt generation

What are the three primary modes of meltwater influence on ice-sheet mass balance?

increased runoff, meltwater injection to the bed and meltwater-induced ice-shelf fracture