A fourth inventory of Antarctic subglacial lakes

Abstract

Antarctic subglacial lakes are studied for three main scientific reasons. First, they form an important component of the basal hydrological system which is known to affect the dynamics of the ice sheet. Second, they are amongst the most extreme viable habitats on Earth and third, if sediments exist on their floors, they may contain high-resolution records of ice sheet history. Here we present a new inventory of locations, dimensions and data sources for 379 subglacial lakes. Several major advances are responsible for the rise in the total number of lakes from the 145 known at the time of the last inventory in 2005. New radar datasets have been collected in previously unexplored regions of the ice sheet while digital data collection and processing techniques have allowed improvements to lake identification methods. Satellite measurements of ice surface elevation change caused by the movement of subglacial water have also been found to be widespread in Antarctica, often in places where radar data are absent. These advances have changed our appreciation of the Antarctic subglacial environment and have expanded our understanding of the behaviour of subglacial lakes.

Ice-flow reorganization within the East Antarctic Ice Sheet deep interior

“…This volume of water is sufficient to fill the SPL and many other lakes known to be in the region (Carter et al 2007;Wright & Siegert 2012). …”

“…Both of these classifications are for locations that satisfy most, but not all, of the criteria for 'definite' subglacial lake detection. 'Definite' lake criteria require bed reflectivity to be relatively and absolutely bright, have high specularity, and be geometrically flat (Wright & Siegert 2012). 'Dim' lakes are characterized by relatively bright and specular reflections, but lack the absolute brightness in reflection expected for an ice-water interface.…”

Modeling Antarctic subglacial lake filling and drainage cycles

“…Subglacial lakes store large quantities of water in bedrock overdeepenings and regions of hydraulic convergence underneath the Antarctic ice sheets, including the highly dynamic ice streams (e.g., Wingham et al, 2006;Wright and Siegert, 2012). The role of these water bodies in ice dynamics is largely unknown and limited by availability of data and knowledge of the basal hydrological regimes.…”

Evidence of rapid subglacial water piracy under Whillans Ice Stream, West Antarctica

“…There are 379 known subglacial lakes under the Antarctic ice sheet, which have been inferred through a variety of remote-sensing techniques (Wright and Siegert, 2012). Before 2005, airborne radar sounding (e.g.…”