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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Variability In The Mass Flux Of The Ross Sea Ice Streams, Antarctica, Over The Last Millennium, Ginny Catania, Christina L. Hulbe, Howard Conway, Ted A. Scambos, C. F. Raymond
Variability In The Mass Flux Of The Ross Sea Ice Streams, Antarctica, Over The Last Millennium, Ginny Catania, Christina L. Hulbe, Howard Conway, Ted A. Scambos, C. F. Raymond
Geology Faculty Publications and Presentations
We synthesize previously published remote-sensing observations, radar data and model output to obtain a ~1000 year ice flow history for the Siple Coast ice-stream system in West Antarctica to investigate the timing and magnitude of changes in mass flux. The synthesized history shows significant short-term variability in ice-stream shear margin and grounding line position due to internal variability of the coupled system. The chronology highlights the interplay between adjacent ice streams, which implies that the behavior of any individual ice stream should not be examined in isolation. Furthermore, individual events cannot be fully interpreted without an understanding of the broad-scale, …
Anisotropic Ice Flow Leading To The Onset Of Ice Stream D, West Antarctica: Numerical Modelling Based On The Observations From Byrd Station Borehole, Weili Wang, H. Jay Zwally, Christina L. Hulbe, Martin J. Siegert, Ian R. Joughin
Anisotropic Ice Flow Leading To The Onset Of Ice Stream D, West Antarctica: Numerical Modelling Based On The Observations From Byrd Station Borehole, Weili Wang, H. Jay Zwally, Christina L. Hulbe, Martin J. Siegert, Ian R. Joughin
Geology Faculty Publications and Presentations
An ice-sheet flowline model is used to simulate the flow of ice along two particle paths toward the onset to Ice Stream D,West Antarctica. One path is near the centre line of the main tributary to the ice stream, while the second passes by the Byrd Station borehole site. In this paper, we analyze the flow of the moderately fast-flowing tributaries in terms of ice-fabric anisotropy and estimate the steady-state ice-flow regions with the compatible developed crystal orientation fabrics along two particle paths. Comparison between modelled isochrones and internal layers detected from radio-echo sounding surveys in the area is used …
Force Balance Along An Inland Tributary And Onset To Ice Stream D, West Antarctica, Stephen F. Price, R. A. Bindschadler, Christina L. Hulbe, Donald D. Blankenship
Force Balance Along An Inland Tributary And Onset To Ice Stream D, West Antarctica, Stephen F. Price, R. A. Bindschadler, Christina L. Hulbe, Donald D. Blankenship
Geology Faculty Publications and Presentations
The transition from inland- to streaming-style ice flow near to and upstream from the onset to Ice Stream D, West Antarctica, is investigated using the force- balance technique. Basal drag provides the majority of the flow resistance over the study area but is substantially modified by non-local stress gradients. Lateral drag increases with distance downstream, balancing ~50-100% of the driving stress at the onset. Longitudinal stress gradients (LSG) are also found to be significant, an observation that distinguishes ice flow in this region from the inland- and streaming-flow regimes that bound it, in which LSG are usually negligible. LSG decrease …
Tributaries To West Antarctic Ice Streams: Characteristics Deduced From Numerical Modelling Of Ice Flow, Christina L. Hulbe, Ian R. Joughin, David L. Morse, R. A. Bindschadler
Tributaries To West Antarctic Ice Streams: Characteristics Deduced From Numerical Modelling Of Ice Flow, Christina L. Hulbe, Ian R. Joughin, David L. Morse, R. A. Bindschadler
Geology Faculty Publications and Presentations
A network of relatively fast-flowing tributaries in the catchment basins of the West Antarctic ice streams transport ice from the inland reservoir to the heads of the ice streams. Branches of the network follow valleys in basal topography, but not all valleys contain tributaries. We investigate the circumstances favoring tributary flow upstream of Ice Streams D and E, using a combination of observation and numerical modelling. No consistent pattern emerges. The transition from tributary to ice-stream flow occurs smoothly along the main tributary feeding into the onset of Ice Stream D, with ice thickness being relatively more important upstream, and …
Evaluation Of Strain Rates On Ice Stream B, Antarctica, Obtained Using Differential Gps, Christina L. Hulbe, I. M. Whillans
Evaluation Of Strain Rates On Ice Stream B, Antarctica, Obtained Using Differential Gps, Christina L. Hulbe, I. M. Whillans
Geology Faculty Publications and Presentations
The "stop-and-go" kinematic Global Positioning System (CPS) technique was used to survey 270 stations twice within a 25 km by 10 km strain grid on the surface of Ice Stream B. One or two geodetic quality receivers operated as reference pivots, while two similar receivers traveled to grid stations. Each station was occupied for 25 s. The method is rapid and reliable. Each survey was completed within 2 weeks. Calculated horizontal strain rates are accurate to 1%. Relative vertical velocities are accurate to 20 mm kmI a-1. Maps of the four horizontal velocity gradients, relative vertical velocity and surface elevation …