ORCID Profile
0000-0002-9731-7498
Current Organisations
University at Buffalo
,
Alexandru Ioan Cuza University
,
University at Buffalo, State University of New York
,
University of Tasmania
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Geomatic Engineering | Geodesy | Oceanography | Glaciology | Geophysics Not Elsewhere Classified | Physical Geography and Environmental Geoscience | Physical Oceanography | Geodesy | Glaciology | Physical Oceanography | Astronomy And Astrophysics | Oceanography Not Elsewhere Classified | Geochronology | Atmospheric Sciences | Information Systems | Natural Resource Management | Climate Change Processes | Interorganisational Information Systems | Information Systems Management | Marine And Estuarine Ecology (Incl. Marine Ichthyology) | Geology Not Elsewhere Classified | Simulation And Modelling | Biological Oceanography | Climatology (Incl. Palaeoclimatology) | Evolutionary Impacts of Climate Change | Special Vehicles | Atmospheric Sciences Not Elsewhere Classified
ANZSRC Socio-Economic Objective (SEO)
Earth sciences | Climate change | Other | Physical sciences | Effects of Climate Change and Variability on Antarctic and Sub-Antarctic Environments (excl. Social Impacts) | Expanding Knowledge in the Earth Sciences | Navy | Information processing services | Biological sciences | Climate variability | Land and water management | Oceanic processes (excl. climate related) | Effects of Climate Change and Variability on Australia (excl. Social Impacts) | Climate Variability (excl. Social Impacts) | Oil and gas | Living resources (flora and fauna) | Oil and Gas Exploration | Natural Hazards in Marine Environments | Expanding Knowledge in the Environmental Sciences | Expanding Knowledge in the Physical Sciences | Ecosystem Assessment and Management of Marine Environments | Coastal and Estuarine Water Management |
Related Links
Publications
Mapping the grounding zone of the Amery Ice Shelf, East Antarctica using InSAR, MODIS and ICESat
Publisher: Cambridge University Press (CUP)
Date: 10-2009
DOI: 10.1017/S095410200999023X
Abstract: We use a combination of satellite techniques (interferometric synthetic aperture radar (InSAR), visible-band imagery, and repeat-track laser altimetry) to develop a benchmark map for the Amery Ice Shelf (AIS) grounding zone (GZ), including its islands and ice rises. The break-in-slope, as an indirect estimate of grounding line location, was mapped for the entire AIS. We have also mapped ∼55% of the landward edge and ∼30% of the seaward edge of the ice shelf flexure boundary for the AIS perimeter. Vertical ice motion from Global Positioning System receivers confirms the location of the satellite-derived GZ in two regions. Our map redefines the extent of floating ice in the south-western AIS and identifies several previously unmapped grounded regions, improving our understanding of the stresses supporting the current dynamical state of the ice shelf. Finally, we identify three along-flow channels in the ice shelf basal topography, approximately 10 km apart, 1.5 km wide and 300–500 m deep, near the southern GZ. These channels, which form at the suture zones between ice streams, may represent zones of potential weakness in the ice shelf and may influence sub-ice-shelf ocean circulation.
Barotropic tides of the Southern Indian Ocean and the Amery Ice Shelf cavity
Publisher: American Geophysical Union (AGU)
Date: 09-2007
DOI: 10.1029/2007GL030900
Circulation of modified Circumpolar Deep Water and basal melt beneath the Amery Ice Shelf, East Antarctica
Publisher: American Geophysical Union (AGU)
Date: 04-2015
DOI: 10.1002/2015JC010697
Abstract: Antarctic ice sheet mass loss has been linked to an increase in oceanic heat supply, which enhances basal melt and thinning of ice shelves. Here we detail the interaction of modified Circumpolar Deep Water (mCDW) with the Amery Ice Shelf, the largest ice shelf in East Antarctica, and provide the first estimates of basal melting due to mCDW. We use subice shelf ocean observations from a borehole site (AM02) situated ∼70 km inshore of the ice shelf front, together with open ocean observations in Prydz Bay. We find that mCDW transport into the cavity is about 0.22 ± 0.06 Sv (1 Sv = 10 6 m 3 s −1 ). The inflow of mCDW drives a net basal melt rate of up to 2 ± 0.5 m yr −1 during 2001 (23.9 ± 6.52 Gt yr −1 from under about 12,800 km 2 of the north‐eastern flank of the ice shelf). The heat content flux by mCDW at AM02 shows high intra‐annual variability (up to 40%). Our results suggest two main modes of subice shelf circulation and basal melt regimes: (1) the “ice pump”/high salinity shelf water circulation, on the western flank and (2) the mCDW meltwater‐driven circulation in conjunction with the “ice pump,” on the eastern flank. These results highlight the sensitivity of the Amery's basal melting to changes in mCDW inflow. Improved understanding of such ice shelf‐ocean interaction is crucial to refining projections of mass loss and associated sea level rise.
Zero-epoch heights and height velocities
Publisher: Informa UK Limited
Date: 1994
Brief communication: widespread potential for seawater infiltration on Antarctic ice shelves
Publisher: Copernicus GmbH
Date: 10-12-2018
Abstract: Abstract. Antarctica's future contribution to sea level change depends on the fate of its fringing ice shelves. One factor which may affect the rate of iceberg calving from ice shelves is the presence of liquid water, including the percolation of seawater into permeable firn layers. Here, we present evidence that most ice shelves around Antarctica have regions where permeable firn exists below sea level. We find that seawater infiltration into ice shelves may be much more widespread in Antarctica than previously recognised. Finally, we identify the locations where seawater infiltration is most likely to occur, with the intention that the results may be used to direct future radar studies.
Do E ast A ustralian C urrent anticyclonic eddies leave the T asman S ea?
Publisher: American Geophysical Union (AGU)
Date: 12-2015
DOI: 10.1002/2015JC011026
A 3D map of englacial attenuation rate from radar reflections at Law Dome, East Antarctica
Publisher: Copernicus GmbH
Date: 27-10-2020
Abstract: Abstract. The East Antarctic Ice Sheet (EAIS) is the largest source of potential sea-level rise, containing approximately 52 m of sea-level equivalent. To constrain estimates of sea-level rise into the future requires knowledge of ice-sheet properties and geometry and ice-penetrating radar offers a means to estimate these properties (e.g. ice thickness, englacial temperatures). One of the regions that have been extensively surveyed using ice-penetrating radar from the Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP) project in East Antarctica is Law Dome, a small independent ice cap situated to the west of Totten Ice Shelf. The ice cap is slow-moving, has a low melt-rate at the surface and moderate wind speeds, making it a useful study site for estimating the radar attenuation. A new method is proposed for the estimation of attenuation rate from radar data which is mathematically modelled as a constrained regularised l2 minimisation problem. In the proposed method, only radar data is required and the englacial reflectors are automatically detected from the radar data itself. To validate our methodology, attenuation differences at flight crossover points are calculated and statistical analyses performed to assess the accuracy of the results. For spatial analyses, the errors are of the order 22.6 %, 15.2 %, and 32.8 % for mean absolute error, median absolute error, and root mean square error respectively. Also, for the depth analyses, up to the depth of 800 m, the errors are under 29.9 %, 24.2 %, and 38.8 % for mean absolute error, median absolute error, and root mean square error respectively. A final product of 3D attenuation rates and uncertainty estimates is provided. The generated dataset is publicly available at 0.25959/5e6851e266f4a (Abdul Salam, 2020).
Interannual variability in the Indian Ocean using altimeter and IX1-expendable bathy-thermograph (XBT) data: Does the 18-month signal exist?
Publisher: American Geophysical Union (AGU)
Date: 10-2006
DOI: 10.1029/2006GL027117
The sea level at Port Arthur, Tasmania, from 1841 to the present
Publisher: American Geophysical Union (AGU)
Date: 04-2003
DOI: 10.1029/2002GL016813
Absolute Calibration in Bass Strait, Australia: TOPEX, Jason-1 and OSTM/Jason-2
Publisher: Informa UK Limited
Date: 07-2011
Vibrations of Mertz Glacier ice tongue, East Antarctica
Publisher: International Glaciological Society
Date: 2012
Abstract: At the time of its calving in February 2010, Mertz Glacier, East Antarctica, was characterized by a 145 km long, 35 km wide floating tongue. In this paper, we use GPS data from the Collaborative Research into Antarctic Calving and Iceberg Evolution (CRAC-ICE) 2007/08 and 2009/10 field seasons to investigate the dynamics of Mertz Glacier. Two months of data were collected at the end of the 2007/08 field season from two kinematic GPS stations situated on each side of the main rift of the glacier tongue and from rock stations located around the ice tongue during 2008/09. Using Precise Point Positioning with integer ambiguity fixing, we observe that the two GPS stations recorded vibrations of the ice tongue with several dominant periods. We compare these results with a simple elastic model of the ice tongue and find that the natural vibration frequencies are similar to those observed. This information provides a better understanding of their possible effects on rift propagation and hence on the glacier calving processes.
The influence of non-static sea ice on Antarctic and Southern Ocean numerical weather prediction
Publisher: Wiley
Date: 12-07-2021
The influence of non-static sea ice on Antarctic and Southern Ocean numerical weather prediction
Publisher: Wiley
Date: 13-11-2022
Velocity change of the Amery Ice Shelf, East Antarctica, during the period 1968–1999
Publisher: American Geophysical Union (AGU)
Date: 03-2007
DOI: 10.1029/2006JF000609
Iceberg calving from the Amery Ice Shelf, East Antarctica
Publisher: International Glaciological Society
Date: 2002
DOI: 10.3189/172756402781817581
Abstract: We investigate the iceberg-calving cycle of the Amery Ice Shelf (AIS), East Antarctica, using evidence acquired between 1936 and 2000. The most recent major iceberg-calving event occurred between late 1963 and early 1964, when a large berg totalling about 10 000 km 2 in area broke from the ice front. The rate of forward advance of the ice front is presently 1300–1400ma –1 . At this rate of advance, based on the present ice-front position from recent RADARSAT imagery, it would take 20–25 years to attain the 1963 (pre-calve) position, suggesting that the AIS calving cycle has a period of approximately 60–70 years. Two longitudinal (parallel-to-flow) rifts, approximately 25 km apart at the AIS front, are observed in satellite imagery acquired over the last 14+years. These rifts have formed at suture zones in the ice shelf, where neighbouring flow-bands have separated in association with transverse spreading. The rifts were 15 km (rift A) and 26 km (rift B) in length in September 2000, and will probably become the sides of a large tabular iceberg (25 km 625 km). Atransverse (perpendicular-to-flow) fracture, visible at the upstream end of rift A in 1996, had propagated 6 km towards rift B by September 2000 when it meets rift B the iceberg will calve. A satellite image acquired in 1962 shows an embayment of this size in the AIS front, hence we deduce that this calving pattern also occurred during the last calving cycle, and therefore that the calving behaviour of the AIS apparently follows a regular pattern.
The influence of lateral mixing on a phytoplankton bloom: Distribution in the Kerguelen Plateau region
Publisher: Elsevier BV
Date: 06-2009
Seismic reflections from pycnoclines in the water column beneath an ice shelf
Publisher: Informa UK Limited
Date: 12-2007
Effect of Deflection Increment Size on Apparent Performance of Fiber Reinforced Concrete Beams and Panels
Publisher: ASTM International
Date: 2011
DOI: 10.1520/JAI103248
Sediment mobility due to currents and waves in the Torres Strait Gulf of Papua region
Publisher: Elsevier BV
Date: 12-2004
Variability of biological production in low wind‐forced regional upwelling systems: A case study off southeastern Australia
Publisher: Wiley
Date: 28-06-2009
DOI: 10.4319/LO.2009.54.5.1548
Abstract: Temporal variability of upwelling activity and primary production is examined for a southeastern Australian upwelling system off the Bonney Coast (36.5°S‐38.5°S, 138°E‐142°E). Three indices of upwelling activity and primary production are developed based on alongshore wind stress, upwelling plume area (anomalous sea surface temperature), and primary productivity of the upwelling plume (approximated using anomalous chlorophyll a concentration). The majority of the upwelling activity occurs during the austral summer upwelling season from November to March. Interannual variability in the wind forcing for this region shows marginal correspondence to El Nino‐Southern Oscillation variability. Intraseasonal variability followed four distinct phases within the upwelling season of "onset," "sustained," "quiescent," and "downwelling" periods. The Bonney Upwelling is a predictable regional system with temporal variability of its physical forcing that is similar to larger, more intensely studied coastal wind‐driven upwelling systems. However, we find that the Bonney Coast is a low wind‐forced upwelling region compared to other upwelling systems. Simple linear quantitative models developed between upwelling activity predictors (wind and upwelling plume area) and the biological response (chlorophyll a) explain 40‐50% of the seasonal variability of approximated phytoplankton productivity along the Bonney Coast. As primary productivity in a low‐wind system is not affected by the deleterious effects of turbulence and advection, these simple models are able to predict chlorophyll variability in the Bonney region. Models developed in this study provide a method of assessing the effect of decadal or longer variability of chlorophyll concentration in low wind‐forcing upwelling systems at regional and global scales.
Antarctic grounding line retreat enhanced by subglacial freshwater discharge
Publisher: Copernicus GmbH
Date: 28-03-2022
DOI: 10.5194/EGUSPHERE-EGU22-6747
Abstract: & & & strong& Accurate prediction of sea level rise requires detailed understanding of processes contributing to ice sheet mass loss. Antarctica& #8217 s ice shelves are thinning, resulting in enhanced flow of grounded ice due to weakened ice shelf buttressing. Glaciers feeding ice shelves with the highest melt rates are also experiencing some of the most rapid grounding zone retreat. However, these ice shelf melt rates reach values that cannot be explained by ocean forcing alone and are not reproduced in ocean models. We present subglacial hydrology model outputs for four major Antarctic glaciers (Pine Island, Thwaites, Totten and Denman), which flow through the deepest and most extensive Antarctic marine subglacial basins and feed rapidly thinning ice shelves. We show that the areas of high ice shelf melting rates and grounding line retreat coincide closely with areas of high subglacial discharge. We posit that the subglacial discharge provides the missing component driving the high melt rates, and identify positive feedbacks between ice dynamics, steepening of ice shelf basal slope, and subglacial outflow. If surface temperatures increase as expected in Antarctica over the coming decades, surface meltwater could flow to the ice sheet base, as observed in Greenland. The surface meltwater hydrological cycle could therefore contribute to seasonal variations in subglacial meltwater and ice shelf basal melt, leading to accelerated grounding line retreat into Antarctica& #8217 s deepest subglacial basins. Invoking these feedbacks could reconcile sea level records and ice sheet model simulations that remain overly stable in warmer periods.& /strong& & &
Seismicity and deformation associated with ice-shelf rift propagation
Publisher: International Glaciological Society
Date: 2007
DOI: 10.3189/002214307784409207
Abstract: Previous observations have shown that rift propagation on the Amery Ice Shelf (AIS), East Antarctica, is episodic, occurring in bursts of several hours with typical recurrence times of several weeks. Propagation events were deduced from seismic swarms (detected with seismometers) concurrent with rapid rift widening (detected with GPS receivers). In this study, we extend these results by deploying seismometers and GPS receivers in a dense network around the tip of a propagating rift on the AIS over three field seasons (2002/03, 2004/05 and 2005/06). The pattern of seismic event locations shows that icequakes cluster along the rift axis, extending several kilometers back from where the rift tip was visible in the field. Patterns of icequake event locations also appear aligned with the ice-shelf flow direction, along transverse-to-rift crevasses. However, we found some key differences in the seismicity between field seasons. Both the number of swarms and the number of events within each swarm decreased during the final field season. The timing of the slowdown closely corresponds to the rift tip entering a suture zone, formed where two ice streams merge upstream. Beneath the suture zone lies a thick band of marine ice. We propose two hypotheses for the observed slowdown: (1) defects within the ice in the suture zone cause a reduction in stress concentration ahead of the rift tip (2) increased marine ice thickness in the rift path slows propagation. We show that the size–frequency distribution of icequakes approximately follows a power law, similar to the well-known Gutenberg–Richter law for earthquakes. However, large icequakes are not preceded by foreshocks nor are they followed by aftershocks. Thus rift-related seismicity differs from the classic foreshock and aftershock distribution that is characteristic of large earth quakes.
THE EARTHS SHAPE AND GRAVITY-FIELD - A REPORT OF PROGRESS FROM 1958 TO 1982 - REPLY
Publisher: Oxford University Press (OUP)
Date: 08-1986
Patterns of Vertical Velocity Induced by Eddy Distortion in an Ocean Model
Publisher: American Geophysical Union (AGU)
Date: 03-2018
DOI: 10.1002/2017JC013298
Structural Monitoring of Cable-Stayed Bridge: Analysis of GPS versus Modeled Deflections
Publisher: American Society of Civil Engineers (ASCE)
Date: 02-2007
SURFACE EDDY MOMENTUM FLUX AND VELOCITY VARIANCES IN THE SOUTHERN-OCEAN FROM GEOSAT ALTIMETRY
Publisher: American Meteorological Society
Date: 10-1994
Treatment of horizontal and vertical tidal signals in GPS data: A case study on a floating ice shelf
Publisher: Springer Science and Business Media LLC
Date: 11-2000
DOI: 10.1186/BF03352328
Ice velocities of the Lambert Glacier from static GPS observations
Publisher: Springer Science and Business Media LLC
Date: 11-2000
DOI: 10.1186/BF03352326
THE EARTHS SHAPE AND GRAVITY-FIELD - A REPORT OF PROGRESS FROM 1958 TO 1982
Publisher: Oxford University Press (OUP)
Date: 07-1983
Classification of the Australian continental shelf based on predicted sediment threshold exceedance from tidal currents and swell waves
Publisher: Elsevier BV
Date: 09-2004
On the low-frequency variability in the Indian Ocean
Publisher: Springer Berlin Heidelberg
Date: 2007
TEMPORAL VARIATIONS IN REGIONAL MODELS OF THE SARGASSO SEA FROM GEOS-3 ALTIMETRY
Publisher: American Meteorological Society
Date: 02-1980
Measurement and assessment of geometric imperfections in thin-walled panels
Publisher: Elsevier BV
Date: 02-1999
The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry
Publisher: American Chemical Society (ACS)
Date: 22-05-2023
Modelled fracture and calving on the Totten Ice Shelf
Publisher: Copernicus GmbH
Date: 24-07-2018
Abstract: Abstract. The Totten Ice Shelf (IS) has a large drainage basin, much of which is grounded below sea level, leaving the glacier vulnerable to retreat through the marine ice sheet instability mechanism. The ice shelf has also been shown to be sensitive to changes in calving rate, as a very small retreat of the calving front from its current position is predicted to cause a change in flow at the grounding line. Therefore understanding the processes behind calving on the Totten IS is key to predicting its future sea level rise contribution. Here we use the Helsinki Discrete Element Model (HiDEM) to show that not all of the fractures visible at the front of the Totten IS are produced locally, but that the across-flow basal crevasses, which are part of the distinctive cross-cutting fracture pattern, are advected into the calving front area from upstream. A separate simulation of the grounding line shows that re-grounding points may be key areas of basal crevasse production, and can produce basal crevasses in both an along- and across-flow orientation. The along-flow basal crevasses at the grounding line may be a possible precursor to basal channels, while we suggest the across-flow grounding-line fractures are the source of the across-flow features observed at the calving front. We use two additional models to simulate the evolution of basal fractures as they advect downstream, demonstrating that both strain and ocean melt have the potential to deform narrow fractures into the broad basal features observed near the calving front. The wide range of factors which influence fracture patterns and calving on this glacier will be a challenge for predicting its future mass loss.
Revisiting the circulation of the East Australian Current: Its path, separation, and eddy field
Publisher: Elsevier BV
Date: 09-2019
On the analysis of repeated geodetic experiments
Publisher: Springer Science and Business Media LLC
Date: 22-06-1999
Geodetic reference systems for crustal motion studies
Publisher: Elsevier
Date: 1979
A decade of change in the hydraulic connection between an Antarctic epishelf lake and the ocean
Publisher: International Glaciological Society
Date: 2012
Abstract: Observations of the water level in Beaver Lake, an epishelf lake in East Antarctica, show a regular tidal signal that is lagged and attenuated from the tides beneath the adjacent Amery Ice Shelf. The phase lag and litude attenuation can be created by a narrow inlet connection between Beaver Lake and the cavity beneath the Amery Ice Shelf. A forced linear d ed oscillator is used to determine the inlet dimensions that are required to produce the observed phase lag and litude attenuation. The model shows that the observations are consistent with a tidal flow that is restricted by the drag created by flow in the narrow inlet. Analysis shows that the phase lag and litude attenuation of the tides in Beaver Lake has increased over the years 1991-2002, probably due to a thickening of the overlying ice shelf. The response is sensitive to subtle variations in the dimensions of the inlet.
Wind forced low frequency variability of the East Australia Current
Publisher: American Geophysical Union (AGU)
Date: 04-2008
DOI: 10.1029/2007GL032912
Redefinition of the Amery Ice Shelf, East Antarctica, grounding zone
Publisher: American Geophysical Union (AGU)
Date: 05-2002
DOI: 10.1029/2001JB000383
Supplementary material to "Brief Communication: Widespread potential for seawater infiltration on Antarctic ice shelves"
Publisher: Copernicus GmbH
Date: 23-07-2018
Comparison between computed balance velocities and GPS measurements in the Lambert Glacier basin, East Antarctica
Publisher: International Glaciological Society
Date: 2003
DOI: 10.3189/172756403781815672
Abstract: Comparisons between computed balance velocities, obtained from two different computing schemes, and global positioning system (GPS)-derived velocities were made in the Lambert Glacier basin region, East Antarctica. The two computing schemes used for the balance-velocity computations (a flowline (FL) scheme (Remy and Minster, 1993) and a finite-difference (BW) scheme (Budd and Warner, 1996 Fricker and others, 2000)) were first evaluated and compared. One of the key issues studied was the spatial resolution of the digital elevation model (DEM), representing the surface topography of the ice sheet, and the sensitivity of the balance velocities to the length of smoothing applied to the DEM. Comparison with the GPS velocities validated the two schemes to within 5–25% but showed the high sensitivity of the flowline method to the length scale of the smoothing. The finite-difference scheme was found to be robust to the chosen smoothing scale, but the balance-velocity values increased when a finer-resolution DEM was used. Both FL and BW computing schemes tended to overestimate the balance velocities in comparison with the GPS values some of this discrepancy can be attributed to ice-sheet sliding.
Surveying the deflection of an arch bridge to sub-millimetre precision
Publisher: Informa UK Limited
Date: 03-1993
Cold ocean cavity and weak basal melting of the Sorsdal Ice Shelf revealed by surveys using autonomous platforms
Publisher: American Geophysical Union (AGU)
Date: 06-2020
DOI: 10.1029/2019JC015882
Abstract: Basal melting of ice shelves is inherently difficult to quantify through direct observations, yet it is a critical factor controlling Antarctic mass balance and global sea‐level rise. While much research attention is paid to larger ice shelves and those experiencing the most rapid change, many smaller, unstudied ice shelves offer valuable insights. Here, we investigate the oceanographic conditions and melting beneath the Sørsdal ice shelf, East Antarctica. We present results from the 2018/2019 Sørsdal deployment of the University of Tasmania's autonomous underwater vehicle nupiri muka . Oceanography adjacent to and beneath the ice shelf front shows a cold and relatively saline environment dominated by Winter Water and Dense Shelf Water, while bathymetry measurements show a deep (∼1,200 m) trough running into the ice shelf cavity. Two multiyear deployments of Autonomous Phase‐sensitive Radar Echo Sounders on the surface of the ice shelf show weak melt rates (average of 1.6 and 2.3 m yr −1 ) with low temporal variability. These observations are supported by numerical ocean model and satellite estimates of melting. We speculate that the presence of a ∼825 m thick (350 m to at least 1,175 m) homogeneous layer of cold, dense water blocks access from warmer waters that intrude into Prydz Bay from offshore, resulting in weak melt rates. However, the newly identified trough means that the ice shelf is vulnerable to any decrease in polynya activity that allows warm water to enter the cavity. This could lead to increased basal melting and mass loss through this sector of Antarctica.
Estimates of the regional distribution of sea level rise over the 1950-2000 period
Publisher: American Meteorological Society
Date: 07-2004
An investigation into the forces that drive ice-shelf rift propagation on the Amery Ice Shelf, East Antarctica
Publisher: International Glaciological Society
Date: 2008
DOI: 10.3189/002214308784409116
Abstract: For three field seasons (2002/03, 2004/05, 2005/06) we have deployed a network of GPS receivers and seismometers around the tip of a propagating rift on the Amery Ice Shelf, East Antarctica. During these c aigns we detected seven bursts of episodic rift propagation. To determine whether these rift propagation events were triggered by short-term environmental forcings, we analyzed simultaneous ancillary data such as wind speeds, tidal litudes and sea-ice fraction (a proxy variable for ocean swell). We find that none of these environmental forcings, separately or together, correlated with rift propagation. This apparent insensitivity of ice-shelf rift propagation to short-term environmental forcings leads us to suggest that the rifting process is primarily driven by the internal glaciological stress. Our hypothesis is supported by order-of-magnitude calculations that the glaciological stress is the dominant term in the force balance. However, our calculations also indicate that as the ice shelf thins or the rift system matures and iceberg detachment becomes imminent, short-term stresses due to winds and ocean swell may become more important.
RECENT CRUSTAL DEFORMATION IN SOUTHEAST AUSTRALIA - FACT OR FICTION
Publisher: Informa UK Limited
Date: 12-1984
Brief Communication: Widespread potential for seawater infiltration on Antarctic ice shelves
Publisher: Copernicus GmbH
Date: 23-07-2018
DOI: 10.5194/TC-2018-146
Abstract: Abstract. Antarctica's future contribution to sea level change depends on the fate of its fringing ice shelves. One variable which may affect the rates of iceberg calving from ice shelves is the presence of liquid water, including the percolation of seawater into permeable firn layers. Here, we present evidence that most ice shelves around Antarctica have regions where permeable firn exists below sea level. The findings indicate that seawater infiltration onto ice shelves may be much more widespread in Antarctica than previously recognised. Our results present the most likely locations for seawater infiltration to occur, and may be used as an indicator of where future radar studies might be focussed.
Toward the widespread application of low-cost technologies in coastal ocean observing (Internet of Things for the Ocean)
Publisher: National Documentation Centre (EKT)
Date: 16-03-2021
DOI: 10.12681/MMS.25060
Abstract: The ability to access user-friendly, low-cost instrumentation remains a limiting factor in coastal ocean observing. The majority of currently available marine observation equipment is difficult to deploy, costly to operate, and requires specific technical skills. Moreover, a harmonized observation program for the world’s coastal waters has not yet been established despite the efforts of the global ocean organizations. Global observational systems are mainly focused on open ocean waters and do not include coastal and shelf areas, where models and satellites require large data sets for their calibration and validation. Fortunately, recent technological advances have created opportunities to improve sensors, platforms, and communications that will enable a step-change in coastal ocean observing, which will be driven by a decreasing cost of the components, the availability of cheap housing, low-cost controller/data loggers based on embedded systems, and low/no subscription costs for LPWAN communication systems. Considering the above necessities and opportunities, POGO’s OpenMODs project identified a series of general needs/requirements to be met in an Open science development framework. In order to satisfy monitoring and research necessities, the sensors to be implemented must be easily interfaced with the data acquisition and transmission system, as well as compliant with accuracy and stability requirements. Here we propose an approach to co-design a cost-effective observing modular instrument architecture based on available low-cost measurement and data transmission technologies, able to be mounted/operated on various platforms. This instrument can fit the needs of a large community that includes scientific research (including those in developing countries), non-scientific stakeholders, and educators.
Assessment of Geoid Models Offshore Western Australia UsingIn-SituMeasurements
Publisher: Coastal Education and Research Foundation
Date: 05-2009
DOI: 10.2112/07-0972.1
SUBSIDENCE AND FLEXURE ALONG THE PRATT-WELKER SEAMOUNT CHAIN
Publisher: Elsevier BV
Date: 02-1984
Coastal Tide Gauge Calibration: A Case Study at Macquarie Island Using GPS Buoy Techniques
Publisher: Coastal Education and Research Foundation
Date: 07-2008
DOI: 10.2112/07-0844.1
Barotropic tides beneath the Amery Ice Shelf
Publisher: American Geophysical Union (AGU)
Date: 11-2006
DOI: 10.1029/2006JC003622
Technique for precise measurement of large-scale silos and tanks
Publisher: American Society of Civil Engineers (ASCE)
Date: 02-1996
Spurious periodic horizontal signals in sub-daily GPS position estimates
Publisher: Springer Science and Business Media LLC
Date: 29-06-2003
Southern Ocean pinnipeds provide bathymetric insights on the East Antarctic continental shelf
Publisher: Springer Science and Business Media LLC
Date: 21-07-2023
DOI: 10.1038/S43247-023-00928-W
Abstract: Poor coverage of the Antarctic continental shelf bathymetry impedes understanding the oceanographic processes affecting Antarctica’s role in global climate. Continental shelf bathymetry influences warm modified Circumpolar Deep Water movement onto the shelf, making it an important factor promoting ice shelf melting and influencing the flow of ice shelves into the ocean. Building on previous work using seal es to redefine bathymetry, our longitudinal study of ocean physics and animal behaviour provided new depth information from over 500,000 in idual seal es on the East Antarctic continental shelf. About 25% of these seal es were 220 m (sometimes over 1000 m) deeper than the interpolated seafloor from IBCSO V2. Focusing on four well-s led regions, we show that the bathymetry of 22% to 60% of the s led area was improved by incorporating seal e data. This revealed new bathymetric features, including troughs off the Shackleton Ice Shelf and Underwood Glacier and a deep canyon near the Vanderford Glacier. This deep canyon, the Mirounga-Nuyina Canyon , was confirmed by a recent multi-beam echo sounder survey. Further acquisitions of seal data will improve our understanding and modelling of Antarctic coastal ocean processes and ice-sheet dynamics.
GPS-DERIVED STRAIN RATES ON AN ACTIVE ICE SHELF RIFT
Publisher: Informa UK Limited
Date: 2009
Dual-frequency altimeter signal from Envisat on the Amery ice-shelf
Publisher: Elsevier BV
Date: 08-2007
Interannual oscillatory modes in the Indian Ocean and predictability of the Indian Ocean dipole
Publisher: World Scientific Publishing Co. Pte. Ltd.
Date: 2011
Digital elevation models for the Lambert Glacier- Amery Ice Shelf System, East Antarctica, from ERS-1 satellite radar altimerty
Publisher: International Glaciological Society
Date: 2000
DOI: 10.3189/172756500781832639
Abstract: The Lambert Glacier–Amery Ice Shelf system is a major component of the East Antarctic ice sheet. This paper presents two digital elevation models (DEMs) that have been generated for the Lambert–Amery system from validated European Remote-sensing Satellite (ERS-1) radar altimeter waveform data. The first DEM covers the Amery Ice Shelf only, and was produced using kriging on a 1 km grid. The second is a coarser (5 km) DEM of the entire Lambert–Amery system, generated via simple averaging procedures. The DEMs provide unprecedented surface elevation information for the Lambert–Amery system and allow new insight into the glaciology of the region.
On the satellite altimeter crossover problem
Publisher: Springer Science and Business Media LLC
Date: 21-01-1997
Twentieth century constraints on sea level change and earthquake deformation at Macquarie Island
Publisher: Oxford University Press (OUP)
Date: 06-2010
Velocities of the Amery Ice Shelf's primary tributary glaciers, 2004-12
Publisher: Cambridge University Press (CUP)
Date: 28-05-2015
DOI: 10.1017/S0954102015000231
Abstract: Monitoring the rate of ice flow into ice shelves is vital to understanding how, where and when mass changes occur in Antarctica. Previous observations of ice surface velocity indicate that the Amery Ice Shelf and tributary glaciers have been relatively stable over the period 1968 to 1999. This study measured the displacement of features on the ice surface over a sequence of Landsat 7 images separated by approximately one year and spanning 2004 to 2012 using the surface feature tracking software IMCORR. The focus is on the region surrounding the southern grounding zone of the Amery Ice Shelf and its primary tributary glaciers: the Fisher, Lambert and Mellor glaciers. No significant changes in surface velocity were observed over this period. Accordingly, the velocity fields from each image pair between 2004 and 2012 were used to synthesize an average velocity dataset of the Amery Ice Shelf region and to compare it to previously published velocity datasets and in situ global positioning system velocity observations. No significant change in ice surface velocities was found between 2004 and 2012 in the Amery Ice Shelf region, which suggests that it continues to remain stable.
Barotrophic tides beneath the Amery Ice Shelf
Publisher: American Geophysical Union (AGU)
Date: 09-09-2006
DOI: 10.1029/2005JC003162
Absolute Calibration of TOPEX/Poseidon and Jason-1 Using GPS Buoys in Bass Strait, Australia
Publisher: Informa UK Limited
Date: 07-2003
DOI: 10.1080/714044522
Variance-covariance estimation of GPS networks
Publisher: Springer Science and Business Media LLC
Date: 06-1994
DOI: 10.1007/BF00819384
Modeling the basal melting and marine ice accretion of the Amery Ice Shelf
Publisher: American Geophysical Union (AGU)
Date: 09-2012
DOI: 10.1029/2012JC008214
Basal melt, seasonal water mass transformation, ocean current variability, and deep convection processes along the Amery Ice Shelf calving front, East Antarctica
Publisher: American Geophysical Union (AGU)
Date: 07-2016
DOI: 10.1002/2016JC011858
A new tide model for the Antarctic ice shelves and seas
Publisher: International Glaciological Society
Date: 2002
DOI: 10.3189/172756402781817752
Abstract: We describe a new tide model for the seas surrounding Antarctica, including the ocean cavities under the floating ice shelves. The model uses data assimilation to improve its fit to available data. Typical peak-to-peak tide ranges on ice shelves are 1–2 m but can exceed 3 m for the Filchner–Ronne and Larsen Ice Shelves in the Weddell Sea. Spring tidal ranges are about twice these values. Model performance is judged relative to the ~5–10 cm accuracy that is needed to fully utilize ice-shelf height data that will be collected with the Geoscience Laser Altimeter System, scheduled to be launched on the Ice, Cloud and land Elevation Satellite in late 2002. The model does not yet achieve this level of accuracy except very near the few high-quality tidal records that have been assimilated into the model. Some improvement in predictive skill is expected from increased sophistication of model physics, but we also require better definition of ice-shelf grounding lines and more accurate water-column thickness data in shelf seas and under the ice shelves. Long-duration tide measurements (bottom pressure gauge or global positioning system) in critical data-sparse areas, particularly near and on the Filchner–Ronne and Ross Ice Shelves and Pine Island Bay, are required to improve the performance of the data-assimilation model.
Investigations of the tasman sea by satellite altimetry
Publisher: CSIRO Publishing
Date: 1984
DOI: 10.1071/MF9840619
Abstract: Altimeter data obtained over a period of 3.6 years (from April 1975 to November 1978) and over the winter period July-September 1978 from the GEOS-3 and SEASAT satellites were used to study the spatial distribution of mesoscale sea-surface variability in the Tasman Sea. Satellite data generally agreed with existing hydrographic measurements. Patterns of higher sea-surface variability were shown to be associated with the East Australian Current and eddy areas. Though the Tasman Front is known to be present at certain times of the year, it is concluded that it is not a permanent feature across the Tasman Sea. Low variability levels in the mid-Tasman Sea are seemingly dictated by the Lord Howe Rise, thus suggesting some sort of topographic influence.
Decadal variability of East Australian Current transport inferred from repeated high‐density XBT transects, a CTD survey and satellite altimetry
Publisher: American Geophysical Union (AGU)
Date: 08-2008
DOI: 10.1029/2007JC004664
The sea level at Port Arthur, Tasmania, from 1841 to the present
Publisher: American Geophysical Union (AGU)
Date: 04-2003
DOI: 10.1029/2002GL016813
Ice-shelf elevation changes due to atmospheric pressure variations
Publisher: International Glaciological Society
Date: 2003
DOI: 10.3189/172756503781830386
Abstract: The inverse barometer effect (IBE) is the isostatic response of ocean surface height to changes in atmospheric pressure ( P air ) at a rate of about 1 cm hPa −1 . The IBE is a significant contributor to variability of ice-shelf surface elevation ( η ice ), as we demonstrate with simultaneous global positioning system measurements of η ice and local measurements of P air from the Amery, Brunt and Ross Ice Shelves, Antarctica. We find that an IBE correction is justified for frequencies ( ω ) covering the “weather band”, 0.03 ω 0.5 cpd (cycles per day). The IBE correction reduces the standard deviation of the weather-band signal of η ice from ∼9 cm to ∼3 cm. With this correction, the largest remaining high-frequency error signal in η ice is the inaccuracy of the present generation of Antarctic tide models, estimated to be of order 10 cm for most of Antarctica.
On the recovery of regional ocean tide models using satellite altimetry
Publisher: Informa UK Limited
Date: 1980
On the recovery of ocean dynamic information from satellite altimetry
Publisher: Informa UK Limited
Date: 1980
Modelled fracture and calving on the Totten Ice Shelf
Publisher: Copernicus GmbH
Date: 30-01-2018
DOI: 10.5194/TC-2018-3
Abstract: Abstract. The Totten Ice Shelf (IS) has a large drainage basin, much of which is grounded below sea level, leaving the glacier vulnerable to retreat through the Marine Ice Shelf Instability mechanism. The ice shelf has also been shown to be sensitive to changes in calving rate, as a very small retreat of the calving front from its current position is predicted to cause a change in flow at the grounding line. Therefore understanding the processes behind calving on the Totten IS is key to predicting its future sea level rise contribution. Here we use the Helsinki Discrete Element Model (HiDEM) to show that calving on the Totten IS is controlled not only by locally produced fractures at the calving front, but is also influenced by basal fractures which are likely produced at the grounding line. Our model results show that regrounding points may be key areas of basal crevasse production, and can produce basal crevasses in both an along and across flow orientation. As well as affecting calving, along flow basal crevasses at the grounding line may be a possible precursor to basal channels. We use two additional models to examine the evolution of basal fractures as they advect downstream, demonstrating that both strain and ocean melt have the potential to deform narrow fractures into the broad basal features observed near the calving front. The wide range of factors which influence fracture patterns and calving on this glacier will be a challenge for predicting its future mass loss.
Energetics of internal tides around the Kerguelen Plateau from modeling and altimetry
Publisher: American Geophysical Union (AGU)
Date: 14-06-2011
DOI: 10.1029/2010JC006515
Multi-year monitoring of rift propagation on the Amery Ice Shelf, East Antarctica
Publisher: American Geophysical Union (AGU)
Date: 2005
DOI: 10.1029/2004GL021036
Assessment of mangrove response to projected relative sea-level rise and recent historical reconstruction of shoreline position
Publisher: Springer Science and Business Media LLC
Date: 14-12-2007
DOI: 10.1007/S10661-006-9212-Y
Abstract: We predict the decadal change in position of three American Samoa mangroves from analysis of a time series of remotely sensed imagery, a geographic information system, tide gauge data, and projections for change in sea-level relative to the mangrove surface. Accurate predictions of changes to coastal ecosystem boundaries, including in response to projected relative sea-level rise, enable advanced planning to minimize and offset anticipated losses and minimize social disruption and cost of reducing threats to coastal development and human safety. The observed mean landward migration of three mangroves' seaward margins over four decades was 25, 64, and 72 mma(-1), 12 to 37 times the observed relative sea-level rise rate. Two of the sites had clear trends in reductions in mangrove area, where there was a highly significant correlation between the change in position of the seaward mangrove margin and change in relative sea-level. Here it can be inferred that the force of sea-level rise relative to the mangrove surface is causing landward migration. Shoreline movement was variable at a third site and not significantly correlated with changing sea-level, where it is likely that forces other than change in relative sea-level are predominant. Currently, 16.5%, 23.4%, and 68.0% of the three mangroves' landward margins are obstructed by coastal development from natural landward migration. The three mangroves could experience as high as a 50.0% reduction in area by the year 2100. A 12% reduction in mangrove area by the year 2100 is possible in the Pacific islands region.
Local crossover analysis of exactly repeating satellite altimeter data
Publisher: Springer Science and Business Media LLC
Date: 15-12-1997
A comparison of computation methods for crustal strains from geodetic measurements
Publisher: Elsevier
Date: 1981
Surface profiling system for measurement of engineering structures
Publisher: American Society of Civil Engineers (ASCE)
Date: 02-1996
Southern Ocean frontal structure and sea-ice formation rates revealed by elephant seals
Publisher: Proceedings of the National Academy of Sciences
Date: 19-08-2008
Abstract: Polar regions are particularly sensitive to climate change, with the potential for significant feedbacks between ocean circulation, sea ice, and the ocean carbon cycle. However, the difficulty in obtaining in situ data means that our ability to detect and interpret change is very limited, especially in the Southern Ocean, where the ocean beneath the sea ice remains almost entirely unobserved and the rate of sea-ice formation is poorly known. Here, we show that southern elephant seals ( Mirounga leonina ) equipped with oceanographic sensors can measure ocean structure and water mass changes in regions and seasons rarely observed with traditional oceanographic platforms. In particular, seals provided a 30-fold increase in hydrographic profiles from the sea-ice zone, allowing the major fronts to be mapped south of 60°S and sea-ice formation rates to be inferred from changes in upper ocean salinity. Sea-ice production rates peaked in early winter (April–May) during the rapid northward expansion of the pack ice and declined by a factor of 2 to 3 between May and August, in agreement with a three-dimensional coupled ocean–sea-ice model. By measuring the high-latitude ocean during winter, elephant seals fill a “blind spot” in our s ling coverage, enabling the establishment of a truly global ocean-observing system.
The cavity under the Amery Ice Shelf, East Antarctica
Publisher: International Glaciological Society
Date: 2008
DOI: 10.3189/002214308787779898
Abstract: Ocean circulation under ice shelves and associated rates of melting and freezing are strongly influenced by the shape of the sub-ice-shelf cavity. We have refined an existing method and used additional in situ measurements to estimate the cavity shape under the Amery Ice Shelf, East Antarctica. A finite-element hydrodynamic ocean-tide model was used to simulate the major tidal constituents for a range of different sub-Amery Ice Shelf cavity water-column thicknesses. The data are adjusted in the largely unsurveyed southern region of the ice-shelf cavity by comparing the complex error between simulated tides and in situ tides, derived from GPS observations. We show a significant improvement in the simulated tides, with a combined complex error of 1.8 cm, in comparison with past studies which show a complex error of ∼5.3 cm. Our bathymetry incorporates ice-draft data at the grounding line and seismic surveys, which have provided a considerable amount of new data. This technique has particular application when the water column beneath ice shelves is inaccessible and in situ GPS data are available.
Impact of solid Earth tide models on GPS coordinate and tropospheric time series
Publisher: American Geophysical Union (AGU)
Date: 2006
DOI: 10.1029/2005GL025538
A SEARCH FOR SEAMOUNTS IN THE SOUTHERN COOK AND AUSTRAL REGION
Publisher: American Geophysical Union (AGU)
Date: 04-1982
Rifting processes and ice-flow modulation observed on Mertz Glacier, East Antarctica
Publisher: International Glaciological Society
Date: 2015
Abstract: We investigated the evolution of two major rifts cutting across Mertz Glacier Tongue, East Antarctica, using a combination of satellite images and 60 day sets of GPS data from two stations deployed either side of the western rift in 2007. The eastern rift began to open in the early 1990s, and the western rift initiated in 2002 in conjunction with the collision of a large iceberg with the tongue. Velocity time series derived from the 2007 GPS data exhibited strong variations at tidal periods modulated by sea-surface height and sea-surface slope and reproduced here with a conceptually simple model. We found that opening of the western rift in 2002 leads to a dramatic change in behavior of the tongue as the large range in velocity (700–2400 m a −1 ) observed in 2000 was largely reduced (1075–1225 m a −1 ) in 2007. Opening of the western rift decoupled the glacier from the transverse loading on the tongue driven by east–west tidal circulation. This loading previously induced time-varying lateral drag, which caused the large velocity range. Our results suggest changes in the mechanical behavior of an ice tongue impact the dynamics of the outlet glacier system and should be considered in longer-term mass-balance evaluations.
Delivering sustained, coordinated and integrated observations of the Southern Ocean for global impact
Publisher: Frontiers Media SA
Date: 08-08-2019
Estimating global shelf sediment mobility due to swell waves
Publisher: Elsevier BV
Date: 09-1998
Seasonal and Interannual Variations of the Leeuwin Current off Western Australia from TOPEX/Poseidon Satellite Altimetry
Publisher: Springer Science and Business Media LLC
Date: 2008
A 4‐decade record of elevation change of the Amery Ice Shelf, East Antarctica
Publisher: American Geophysical Union (AGU)
Date: 30-01-2009
DOI: 10.1029/2008JF001094
Episodic propagation of a rift on the Amery Ice Shelf, East Antarctica
Publisher: American Geophysical Union (AGU)
Date: 03-2005
DOI: 10.1029/2004GL022048
TOPEX/Poseidon and Jason-1: Absolute calibration in Bass Strait, Australia
Publisher: Informa UK Limited
Date: 2004
Related Organisations
Laboratoire De Physique Subatomique Et Des Technologies Associees
Location: France
University At Buffalo, State University Of New York
Location: United States of America
Related Funding Activities
Winter Temperature And Salinity Profile Measurements In The Southern Ocean Using Elephant Seals As Ocean Sampling Platforms
Start Date: 2003
End Date: 2005
Funder: Australian Research Council
View Funded ActivityNCRIS 5.13 Structure And Evolution Of The Australian Continent [AuScope Component Geospatial Very Long Baseline Interferometry VLB1 Equipment]
Start Date: 2007
End Date: 2013
Funder: Department of Industry and Science
View Funded ActivityAntarctic Climate And Ecosystems Cooperative Research Centre (ACE CRC)
Start Date: 2014
End Date: 2019
Funder: Department of Industry and Science
View Funded ActivityQuantifying Sea-level Trends And Extremes Along Australia's Coastal Margin
Start Date: 2015
End Date: 2017
Funder: Australian Research Council
View Funded ActivityLooking Back To See The Future: Change In The Lambert Glacier And The East Antarctic Ice Sheet
Start Date: 2003
End Date: 2006
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE0236393
Start Date: 2001
End Date: 12-2002
Amount: $175,000.00
Funder: Australian Research Council
View Funded ActivitySpecial Research Initiatives - Grant ID: SR140300001
Start Date: 07-2014
End Date: 06-2020
Amount: $24,000,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0666733
Start Date: 12-2006
End Date: 12-2009
Amount: $290,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0345010
Start Date: 01-2003
End Date: 06-2007
Amount: $250,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP220102969
Start Date: 05-2022
End Date: 05-2025
Amount: $525,000.00
Funder: Australian Research Council
View Funded ActivityResearch Networks - Grant ID: RN0460181
Start Date: 12-2004
End Date: 12-2010
Amount: $1,950,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE0232306
Start Date: 2001
End Date: 12-2002
Amount: $190,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0342704
Start Date: 2003
End Date: 12-2007
Amount: $530,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP0212077
Start Date: 08-2002
End Date: 12-2008
Amount: $443,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP150100615
Start Date: 05-2015
End Date: 12-2021
Amount: $435,500.00
Funder: Australian Research Council
View Funded ActivitySpecial Research Initiatives - Grant ID: SR200100008
Start Date: 08-2021
End Date: 12-2027
Amount: $20,000,000.00
Funder: Australian Research Council
View Funded ActivitySpecial Research Initiatives - Grant ID: SR0354683
Start Date: 12-2003
End Date: 12-2004
Amount: $10,000.00
Funder: Australian Research Council
View Funded ActivitySpecial Research Initiatives - Grant ID: SR0354575
Start Date: 01-2004
End Date: 06-2004
Amount: $30,000.00
Funder: Australian Research Council
View Funded Activity