A mini‐corer for precision sampling of the water‐sediment interface in subglacial lakes and other remote aqueous environments (original) (raw)

Probe technologies for clean sampling and measurement of subglacial lakes

Philosophical transactions. Series A, Mathematical, physical, and engineering sciences, 2016

It is 4 years since the subglacial lake community published its plans for accessing, sampling, measuring and studying the pristine, and hitherto enigmatic and very different, Antarctic subglacial lakes, Vostok, Whillans and Ellsworth. This paper summarizes the contrasting probe technologies designed for each of these subglacial environments and briefly updates how these designs changed or were used differently when compared to previously published plans. A detailed update on the final engineering design and technical aspects of the probe for Subglacial Lake Ellsworth is presented. This probe is designed for clean access, is negatively buoyant (350 kg), 5.2 m long, 200 mm in diameter, approximately cylindrical and consists of five major units: (i) an upper power and communications unit attached to an optical and electrical conducting tether, (ii)-(iv) three water and particle samplers, and (v) a sensors, imaging and instrumentation pack tipped with a miniature sediment corer. To date...

Technologies for retrieving sediment cores in Antarctic subglacial settings

Philosophical transactions. Series A, Mathematical, physical, and engineering sciences, 2016

Accumulations of sediment beneath the Antarctic Ice Sheet contain a range of physical and chemical proxies with the potential to document changes in ice sheet history and to identify and characterize life in subglacial settings. Retrieving subglacial sediments and sediment cores presents several unique challenges to existing technologies. This paper briefly reviews the history of sediment sampling in subglacial environments. It then outlines some of the technological challenges and constraints in developing the corers being used in sub-ice shelf settings (e.g. George VI Ice Shelf and Larsen Ice Shelf), under ice streams (e.g. Rutford Ice Stream), at or close to the grounding line (e.g. Whillans Ice Stream) and in subglacial lakes deep under the ice sheet (e.g. Lake Ellsworth). The key features of the corers designed to operate in each of these subglacial settings are described and illustrated together with comments on their deployment procedures.

Antarctic subglacial lake exploration: first results and future plans

Philosophical transactions. Series A, Mathematical, physical, and engineering sciences, 2016

After more than a decade of planning, three attempts were made in 2012-2013 to access, measure in situ properties and directly sample subglacial Antarctic lake environments. First, Russian scientists drilled into the top of Lake Vostok, allowing lake water to infiltrate, and freeze within, the lower part of the ice-core borehole, from which further coring would recover a frozen sample of surface lake water. Second, UK engineers tried unsuccessfully to deploy a clean-access hot-water drill, to sample the water column and sediments of subglacial Lake Ellsworth. Third, a US mission successfully drilled cleanly into subglacial Lake Whillans, a shallow hydraulically active lake at the coastal margin of West Antarctica, obtaining samples that would later be used to prove the existence of microbial life and active biogeochemical cycling beneath the ice sheet. This article summarizes the results of these programmes in terms of the scientific results obtained, the operational knowledge gaine...

Exploration of Ellsworth Subglacial Lake: A concept paper on the development, organisation and execution of an experiment to explore, measure and sample the environment of a West Antarctic subglacial lake: The Lake Ellsworth Consortium

Abstract Antarctic subglacial lakes have, over the past few years, been hypothesised to house unique,forms,of life and hold detailed sedimen- tary records of past climate change. Testing this hypothesis,requires,in situ examinations.,The direct measurement,of subglacial lakes has been considered,ever since the largest and best-known lake, named Lake Vostok, was identified as having,a deep,water-column.,The,Subglacial Antarctic,Lake,Environments,(SALE) M. J. Siegert (&)