A5001595589- Cryospheric studies and observations
- Climate change and permafrost
- Landslides and related hazards
- Winter Sports Injuries and Performance
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Environmental and Cultural Studies in Latin America and Beyond
- Polar Research and Ecology
- Methane Hydrates and Related Phenomena
- Seismic Waves and Analysis
- Trauma, Hemostasis, Coagulopathy, Resuscitation
- Blood transfusion and management
- Hydrology and Watershed Management Studies
- Geophysics and Gravity Measurements
- Hemoglobin structure and function
- GNSS positioning and interference
- Youth Development and Social Support
- Seismic Imaging and Inversion Techniques
- Groundwater flow and contamination studies
- Atmospheric chemistry and aerosols
- Hydrological Forecasting Using AI
- Crime, Deviance, and Social Control
- Evacuation and Crowd Dynamics
- School Health and Nursing Education
- Environmental Monitoring and Data Management
UNSW Sydney
2025
International Centre for Integrated Mountain Development
2022-2024
Norwegian Water Resources and Energy Directorate
2008-2019
Norsk Hydro (Norway)
2003-2018
Planetary Science Institute
1997
California Institute of Technology
1997
The Ohio State University
1990
The basal regions of continental ice sheets are gaps in our current understanding the Earth's biosphere and biogeochemical cycles. We draw on existing new chemical data sets for subglacial meltwaters to provide first comprehensive assessment sub‐ice sheet weathering. show that size mass is a critical control balance weathering processes microbial activity ubiquitous driving dissolution. Carbonate dissolution fueled by sulfide oxidation CO 2 dominate beneath small valley glaciers. Prolonged...
Glacier movement is resisted partially by debris, either within glaciers or under in water-saturated layers. In experiments beneath a thick, sliding glacier, ice containing 2 to 11% debris exerted shear traction of 60 200 kilopascals on smooth rock bed, comparable the total and contrary usual assumption that debris-bed friction negligible. Imposed pore-water pressure was 100% normal stress subglacial layer reduced sufficiently halt its deformation cause slip over debris. Slip resistance thus...
Abstract Aquatic dissolved organic matter (DOM) is a major reservoir of reduced carbon and has significant influence on heterotrophic biological productivity water quality in marine freshwater environments. Although the forms transformations DOM temperate aquatic soil environments have been studied extensively, this not case for glacial In study, fluorescent excitation–emission matrices (EEMs), parallel factor analysis (PARAFAC) cluster were used to characterize fluorescing components ice...
Abstract To ascertain whether the velocity of Ice Stream B, West Antarctica, may be controlled by stresses in its marginal shear zones (the “Snake” and “Dragon”), we undertook a determination stress Dragon near Camp Up B using ice itself as meter. The observed strain rate 0.14 −1 is used to calculate from flow law determined creep tests on cores depth 300 m Dragon, obtained hot-water ice-coring drill. test-specimen orientation relative axes chosen basis c -axis fabrics so that test applies...
Field measurements of debris‐bed friction on a smooth rock tablet at the bed Engabreen, hard‐bedded, temperate glacier in northern Norway, indicated that basal ice containing 10% debris by volume exerted local shear traction up to 500 kPa. The corresponding bulk coefficient between dirty and was 0.05 0.08. A model which nonrotating spherical particles are held frictional contact with bed‐normal flow can account for these if power law exponent flowing past large clasts is 1. small ( n < 2)...
Abstract To avoid some of the limitations studying soft-bed processes through boreholes, a prism simulated till (1.8 m × 1.6 0.45 m) with extensive instrumentation was constructed in trough blasted rock bed Engabreen, temperate glacier Norway. Tunnels there provide access to beneath 213 ice. Pore-water pressure regulated by pumping water it. During experiments lasting 7–12 days, regelated downward into depths 50–80 mm, accreting ice-infiltrated at rates predicted theory. periods sustained...
New laboratory experiments exploring likely subglacial conditions reveal controls on the transition between stable sliding and stick‐slip motion of debris‐laden ice over rock, with implications for glacier behavior. Friction a rock substrate clasts in generates heat, which melts nearby to produce lubricating water. An increase speed or an entrained debris raises heat generation thus meltwater production. Unstable is favored by low initial lubrication followed rapid production response...
Probably the most important mechanism of glacial erosion is quarrying: growth and coalescence cracks in subglacial bedrock dislodgement resultant rock fragments. Although evidence indicates that rates depend on sliding speed, crack may be enhanced by changing stresses bed caused fluctuating basal water pressure zones ice‐bed separation. To study quarrying real time, a granite step, 12 cm high with its stoss surface, was installed at Engabreen, Norway. Acoustic emission sensors monitored...
Abstract Understanding changes in glacier mass balances is essential for investigating climate changes. However, glacier‐wide determined from geodetic observations do not provide a relevant climatic signal as they depend on the dynamic response of glaciers. In situ point balance measurements direct but show strong spatial variability that difficult to assess heterogeneous over several decades. To address this issue, we propose nonlinear statistical model takes into account and temporal...
Abstract Repeat aerial photography is used to obtain closely spaced measurements of velocity and elevation over a complete transect Ice Stream tributary B2, including the shear margins, fast ice stream several unusual features, as well UpB camp. Persistent mainly crevasses, are tracked provide 1541 values 1933 elevation. These describe flow in stream. Within stream, dominant gradient lateral shear. Crevasse patterns studied relation measured gradients. Crevasses intersect one another at...
Abstract Assessing the impact of possible climate change on water resources glacierized areas requires a reliable model climate–glacier-mass-balance relationship. In this study, we simulate mass-balance evolution Engabreen, Norway, using simple based daily temperature and precipitation data from nearby station. Ablation is calculated distributed temperature-index method including potential direct solar radiation, while accumulation linearly with elevation. The was run for period...
Abstract Basal pressure has been recorded at the Svartisen Subglacial Laboratory, northern Norway, for 20 years, and is measured by load cells installed ice–rock interface under ~200m of glacier ice. Synchronous variations between are investigated as evidence stress redistribution hydrological bed connectivity. A running Pearson correlation used to study temporal variation in response several sensors. By studying nature this well sensor pairs, it possible investigate evolution degree...
Snow avalanches are a complex phenomenon and correctly assessing avalanche danger is crucial in order to avoid accidents. To aid the decision-making process, different frameworks (DMFs) have been developed. However, each DMF assesses factors. We identified 44 factors included ten most commonly used DMFs, supplemented by nine regarded as important professionals, resulting 53 classify describe factor's possible strengths, weaknesses limitations. Many shared but there differences when it comes...
Abstract Rock tunnels beneath Engabreen, northern Norway, permit access to the ice-bedrock interface a 210 m thick glacier. Eight load cells have been installed in bedrock of glacier sole along 22 transect. With some interruptions, logged at 15 min intervals since December 1992; here we analyse records until 2003. Load-cell signals measure stresses acting normal bedrock, and usually log pressure thin water film between basal ice bed. Occasionally there are distinct events, characterized by...
Abstract Key issues of glacier monitoring are changes in geometry and mass. As accurate direct measurements costly time-consuming, the use various remote-sensing data for is explored. One technology used described here airborne laser scanning. The method enables derivation high-quality digital elevation models (DEMs) with a vertical horizontal accuracy sub-metre range. Between September 2001 August 2002, three scanner acquisition flights were carried out, covering whole area Engabreen,...
Abstract The geodetic mass balance of the western Svartisen ice cap in northern Norway is determined, this work, from photogrammetry on vertical aerial photographs taken 1968, 1985 and 2002. existing 1968 digital terrain model (DTM) was generated using analogue photogrammetry, 2002 DTMs are newly photogrammetry. for 1968–85 –2.6 ± 0.8mw.e., 1985–2002 it –2.0 1.6mw.e. area decreased 190 km 2 to 187 184 outlet glacier Flatisen southeast retreated 1700 m over two periods. also determined...
Abstract We apply a linear model of orographic precipitation (LT model) to estimate snow accumulation on the western Svartisen ice cap (220 km 2 ) in northern Norway. This combines 3D airflow dynamics with simple parameterizations cloud physics. The is forced by large‐scale atmospheric input variables taken from ECMWF Re‐analysis (ERA‐40) European Center for Medium Range Weather Forecast (ECMWF), and parameters are kept constant entire simulation period, after optimization. domain covers 120...