Abstract
AbstractSubglacial sediments have the potential to reveal information about the controls on glacier flow, changes in ice-sheet history and characterise life in those environments. Retrieving sediments from beneath the ice, through hot water drilled access holes at remote field locations, present many challenges. Motivated by the need to minimise weight, corer diameter and simplify assembly and operation, British Antarctic Survey, in collaboration with UWITEC, developed a simple mechanical percussion corer. At depths over 1000 m however, manual operation of the percussion hammer is compromised by the lack of clear operator feedback at the surface. To address this, we present a new auto-release-recovery percussion hammer mechanism that makes coring operations depth independent and improves hammer efficiency. Using a single rope tether for both the corer and hammer operation, this modified percussion corer is relatively simple to operate, easy to maintain, and has successfully operated at a depth of >2130 m.
Highlights
Introduction and historySubglacial environments remain largely unexplored with most data coming from geophysical observations such as radar and seismics, with very little direct sampling from beneath ice shelves and ice sheets
Sediment corers have been developed for recovering cores via hot water drilled access holes and summaries of corers developed for use in subglacial environments are given in Hodgson and others (2016) and Gong and others (2019)
A new hammer mechanism has been successfully retrofitted to the existing BAS-UWITEC sediment corer
Summary
Subglacial environments remain largely unexplored with most data coming from geophysical observations such as radar and seismics, with very little direct sampling from beneath ice shelves and ice sheets. Hot water drilling is the preferred method of subglacial access beneath thick ice shelves and grounded ice Sediment corers have been developed for recovering cores via hot water drilled access holes and summaries of corers developed for use in subglacial environments are given in Hodgson and others (2016) and Gong and others (2019). These include details of the aims, logistical constraints, technological challenges and key features of the coring system. As hot water drill depth capabilities increase, reliable methods of retrieving sediment cores from greater depths must be developed. We describe the original BAS-UWITEC percussion corer, manually operated via a single surface rope tether, and a new auto-release-recovery percussion hammer mechanism designed to maintain reliable percussive coring operations at much greater depths
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
