A5059210244- Cryospheric studies and observations
- Winter Sports Injuries and Performance
- Arctic and Antarctic ice dynamics
- Geology and Paleoclimatology Research
- Polar Research and Ecology
- Landslides and related hazards
- Climate change and permafrost
- Climate variability and models
- Oceanographic and Atmospheric Processes
- Adventure Sports and Sensation Seeking
- Methane Hydrates and Related Phenomena
- Meteorological Phenomena and Simulations
- Nuclear Physics and Applications
- Remote Sensing and LiDAR Applications
- Satellite Image Processing and Photogrammetry
- Hydrology and Watershed Management Studies
- Aquatic and Environmental Studies
- Seismic Imaging and Inversion Techniques
- Marine Biology and Environmental Chemistry
- Ship Hydrodynamics and Maneuverability
- High Altitude and Hypoxia
- Aerospace Engineering and Energy Systems
- Marine animal studies overview
- Icing and De-icing Technologies
- Geophysics and Gravity Measurements
British Antarctic Survey
2012-2025
Natural Environment Research Council
2002-2020
Abstract Thwaites Glacier represents 15% of the ice discharge from West Antarctic Ice Sheet and influences a wider catchment 1–3 . Because it is grounded below sea level 4,5 , thought to be susceptible runaway retreat triggered at grounding line (GL) which glacier reaches ocean 6,7 Recent ice-flow acceleration 2,8 front 8–10 GL 11,12 indicate that loss will continue. The relative impacts mechanisms underlying recent are however uncertain. Here we show sustained least 2011 2020 resolve...
Abstract Thwaites Glacier is one of the fastest-changing ice–ocean systems in Antarctica 1–3 . Much ice sheet within catchment grounded below sea level on bedrock that deepens inland 4 , making it susceptible to rapid and irreversible loss could raise global by more than half a metre 2,3,5 The rate extent loss, whether proceeds irreversibly, are set ocean conditions basal melting grounding-zone region where first goes afloat 3,6 both which largely unknown. Here we show—using observations...
Research Article| February 01, 2007 Rapid erosion, drumlin formation, and changing hydrology beneath an Antarctic ice stream A.M. Smith; Smith 1British Survey, Natural Environment Council, Madingley Road, Cambridge CB3 0ET, UK Search for other works by this author on: GSW Google Scholar T. Murray; Murray 2University of Wales Swansea, Singleton Park, Swansea SA2 8PP, K.W. Nicholls; Nicholls 3British K. Makinson; Makinson G. Ađalgeirsdóttir; Ađalgeirsdóttir 4University A.E. Behar; Behar 5Jet...
Abstract. Sub-ice shelf circulation and freezing/melting rates in ocean general models depend critically on an accurate consistent representation of cavity geometry. Existing global or pan-Antarctic topography data sets have turned out to contain various inconsistencies inaccuracies. The goal this work is compile independent regional surveys maps into a set. We use the S-2004 1-min bathymetry as backbone add improved version BEDMAP (ALBMAP bedrock topography) for area that roughly coincides...
An isopycnic coordinate ocean circulation model is applied to the cavity beneath Filchner-Ronne Ice Shelf, investigating role of tides on sub-ice shelf and ice basal mass balance.Including tidal forcing causes a significant intensification in circulation, with an increase melting (3-fold) refreezing (6-fold); net melt rate seawater flux through approximately doubles.With forcing, spatial pattern magnitude freezing generally match observations.The 0.22 m -1 close satellite-derived estimates...
Recent GPS observations from a spatially extensive network across Ronne Ice Shelf show significant daily ice flow variations. At all sites, the almost‐synchronous horizontal displacements occur at diurnal and semidiurnal tidal periods. During spring tides, displacements, velocities strains near front have superimposed oscillations that are ±300% of their mean values over six‐hour period, resulting in regular shelf reversals. Close to stream grounding lines, however, signals decay almost...
Abstract In the early hours of 25 December 2012, an attempt to explore Subglacial Lake Ellsworth, West Antarctica, using a specially designed hot-water drill, was halted. This UK project, involving several universities, British Antarctic Survey and National Oceanography Centre, had been in planning for 10 years. The project developed full blueprint subglacial lakes research, access environment through deep drilling, direct measurement sampling water sediment by construction probe corer,...
Abstract Three holes were drilled to the bed of Rutford Ice Stream, through ice up 2154 m thick, investigate basal processes and conditions associated with fast flow glacial history West Antarctic Sheet. A narrative drilling, measuring sampling activities, as well some preliminary results initial interpretations subglacial conditions, is given. These deepest access ever using hot-water drilling method. Samples englacial sediments recovered, a number instruments installed in column bed. The...
Abstract Thwaites Glacier is one of the fastest‐changing ice‐ocean systems in Antarctica. Basal melting beneath Thwaites' floating ice shelf, especially around pinning points and at grounding line, sets rate loss contribution to global sea‐level rise. The basal controlled by transport heat into through ice–ocean boundary layer toward base. Here we present first turbulence observations from line Eastern Ice Shelf. We demonstrate that contrary expectations, turbulence‐driven vertical flux...
A depth‐averaged tidal model has been applied to the southern Weddell Sea. The domain covers continental shelf, including ocean cavity beneath Filchner‐Ronne Ice Shelf. Reasonable agreement with available current meter data achieved. Our results confirm that in areas shallow water and large topographic gradients, oscillations peak velocities up 1 m s −1 play a significant role vertical mixing transport of masses. estimated energy dissipation Shelf due surface friction is 25 GW, approximately...
We have made oceanographic measurements at two sites beneath the southern Filchner‐Ronne Ice Shelf. Hot‐water drilled access holes were during January 1999, allowing conductivity‐temperature‐depth (CTD) profiling and deployment of instrument moorings. The CTD profiles show that entire water column is below surface freezing point. estimate (summer) flux between to be 2×10 6 m 3 s −1 . summer potential temperature‐salinity properties suggest this flow part a recirculation in deepest subice...
To capture the austral summer to winter transition in water mass properties over southern Weddell Sea continental shelf and slope region, 19 seals were tagged with miniaturized conductivity–temperature–depth sensors February 2011. During following 8 months instruments yielded about 9000 temperature–salinity profiles from a previously undersampled area. This allows, for first time, description of seasonality warm intrusions onto shelf, as well its southward extent towards Filchner Ice Shelf....
Abstract The 2011/12 Antarctic field season saw the first use of a new British Survey (BAS) ice-shelf hot-water drill system on Larsen C and George VI ice shelves. Delivering 90 L min −1 at 80°C, total five holes >30 cm in diameter three locations were successfully drilled through almost 400 m to provide access underlying ocean, including beneath shelf. These enabled deployment instruments measure sea-water conductivity, temperature, depth microstructure, collection water samples up 2.9...
Abstract. Seismic reflection soundings of ice thickness and seabed depth were acquired on the Larsen C Ice Shelf in order to test a sub-ice shelf bathymetry model derived from inversion IceBridge gravity data. A series lines was collected, Churchill Peninsula north Joerg south, also towards front. Sites selected using free-air data indicate key regions where oceanic circulation may be affected by draft depth. The seismic velocity profile upper 100 m firn shallow refraction surveys at number...
Abstract During the 2018/19 Antarctic field season, British Survey (BAS) Basal conditions on Rutford Ice Stream: BEd Access, Monitoring and Sheet History’ (BEAMISH) project drilled three holes through Stream, West Antarctica. At up to 2154 m, these are deepest hot water subglacial access yet created, enabling recovery of sediment from environment, instrumenting ice stream its bed. The BEAMISH hot-water drill system was built extensive experience with BAS shelf utilises many identical...
[1] We report on three GPS records of flow the Larsen C Ice Shelf, spanning 2 months to years. Variations in speed are evident at periods from a few hours ∼182 days, including semi-diurnal, diurnal and ∼14.76 days. At fortnightly ice shelf varies by ±10% its long-term but timescales it is up ±100%. A nonlinear relationship between ocean tides velocity required explain observed variations flow. As an initial examination we model as non-linear function basal shear stress tidal perturbations...
Abstract Cold and dense ice shelf water (ISW) emerging from the Filchner‐Ronne Ice Shelf cavity in southwestern Weddell Sea flows northward through Filchner Depression to eventually descend continental slope contribute formation of bottom water. New ship‐born observations hydrography currents January 2013 suggest that flow ISW takes place a middepth jet along eastern flank depression, thus questioning traditional view with outflow western flank. This interpretation data is supported by...
Abstract Recent drilling successes on Rutford Ice Stream in West Antarctica demonstrate the viability of hot water subglacial access holes to depths >2000 m. Having techniques deep environments reliably paves way for lake exploration beneath thick central Antarctic Sheet. An ideal candidate lake, overlain by ~2650 m ice, identified Centro de Estudios Científicos (CECs), Chile, has led collaboration with British Survey Subglacial Lake CECs (SLCECs). To conform Scientific Committee Research...
Hot‐water drilled access holes were used to obtain oceanographic data from beneath two sites on Larsen C Ice Shelf, one in the north and south. At both entire water column was colder than surface freezing point, temperature‐salinity characteristics are consistent with a High Salinity Shelf Water source of maximum salinity 34.65 psu. southern site 0.08°C thermal driving at ice base 0.2‐m s −1 rms speed resulted melt rate 1.3 ± 0.2 m , as measured over an eight‐day period. When combined...
The Filchner‐Ronne Ice Shelf experiences strong tidal forcing known to displace portions of the ice shelf by several meters over a cycle. These large periodic displacements may cause significant variation vertical strain. Further, currents in cavity be responsible for basal melt variations. We deployed autonomous phase‐sensitive radio‐echo sounders at 17 locations across and measured motion internal sufficiently short intervals allow resolution all constituents. Basal estimates with this...