Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Keyword
-
- Climate Change (6)
- Glaciology (4)
- Geochemistry (3)
- Glaciogeology (3)
- Antarctic Glaciology (2)
-
- Cryology (2)
- Antarctic warming (1)
- Climatic changes -- Antarctic regions (1)
- Climatic changes -- Antarctica (1)
- Compression test (1)
- Ductility (1)
- Experimental study (1)
- Flow Competence (1)
- Flow stress (1)
- Geomorphology (1)
- Glacial Mapping (1)
- Glacial climates -- Antarctica (1)
- Glaciochemistry (1)
- Global warming (1)
- HEC-RAS (1)
- Ice crystals (1)
- Ice sheets -- Antarctica (1)
- Ice shelves -- Effect of climatic change (1)
- Laboratory study (1)
- Mechanical properties (1)
- Pennsylvania (1)
- Restrictions (1)
- Single crystal (1)
- Slippery Rock Creek (1)
- Solubility (1)
- Publication
- Publication Type
Articles 1 - 10 of 10
Full-Text Articles in Glaciology
Powre: High-Resolution Chronology Of Millennial-Scale Lake-Level Fluctuations In The Dry Valleys (Antarctica) From Uranium-Thorium And Radiocarbon Dating, Brenda L. Hall
University of Maine Office of Research Administration: Grant Reports
The Professional Opportunities for Women in Research and Engineering (POWRE) program affords new research and educational enhancement opportunities for women scientists. This project, which addresses the fundamental problem of the cause of millennial-scale climate change, contains components specifically designed to increase the educational and research skills of the principal investigator. She will learn the following new information/skills: 1) thermal ionization mass spectrometry (TIMS) uranium/thorium (U/TH) dating with Dr. G. Henderson at Lamont-Doherty Earth Observatory (LDEO) and Oxford University, 2) millennial-scale climate change with Drs. W. Broecker and G. Bond, LDEO, and with Drs. D. Oppo and L. Keigwin, Woods Hole …
The Effects Of Sulfuric Acid On The Mechanical Properties Of Ice Single Crystals, Y. L. Trickett, I. Baker, P. M.S Pradhan
The Effects Of Sulfuric Acid On The Mechanical Properties Of Ice Single Crystals, Y. L. Trickett, I. Baker, P. M.S Pradhan
Dartmouth Scholarship
Ice single crystals of various orientations containing various concentrations of H2SO4 up to 11.5 ppm were cut from large pucks of laboratory-grown ice. Constant-strain-rate compression tests were performed on the doped ice crystals both at −20°C at an axial strain rate of 1 × 10−5 s−1 and at −10°C at 1 × 106 s−1. The stress–strain curves showed a linearly rising stress with increasing strain, followed by a sharply declining stress after reaching a peak. With further strain, the sharp decline in stress slowed. The tests clearly showed, for the first time, that this naturally occurring impurity dramatically decreases both …
The Effect Of Spatial And Temporal Accumulation Rate Variability In West Antarctica On Soluble Ion Deposition, K. J. Kreutz, Paul Andrew Mayewski, L. D. Meeker, M. S. Twickler, S. I. Whitlow
The Effect Of Spatial And Temporal Accumulation Rate Variability In West Antarctica On Soluble Ion Deposition, K. J. Kreutz, Paul Andrew Mayewski, L. D. Meeker, M. S. Twickler, S. I. Whitlow
Earth Science Faculty Scholarship
Annually‐dated snowpit and ice core records from two areas of West Antarctica are used to investigate spatial accumulation patterns and to evaluate temporal accumulation rate/glaciochemical concentration and flux relationships. Mean accumulation rate gradients in Marie Byrd Land (11–23 gcm−2yr−1 over 150 km, decreasing to the south) and Siple Dome (10–18 gcm−2yr−1 over 60 km, decreasing to the south) are consistent for at least the last several decades, and demonstrate the influence of the offshore quasi‐permanent Amundsen Sea low pressure system on moisture flux into the region. Local and regional‐scale topography in both regions appears …
Sea Level Pressure Variability In The Amundsen Sea Region Inferred From A West Antarctic Glaciochemical Record, K. J. Kreutz, Paul Andrew Mayewski, I. I. Pittalwala, L. D. Meeker, M. S. Twickler, S. I. Whitlow
Sea Level Pressure Variability In The Amundsen Sea Region Inferred From A West Antarctic Glaciochemical Record, K. J. Kreutz, Paul Andrew Mayewski, I. I. Pittalwala, L. D. Meeker, M. S. Twickler, S. I. Whitlow
Earth Science Faculty Scholarship
Using European Center for Medium-Range Weather Forecasts (ECMWF) numerical operational analyses, sea ice extent records, and station pressure data, we investigate the influence of sea level pressure variability in the Amundsen Sea region on a West Antarctic (Siple Dome) glaciochemical record. Empirical orthogonal function analysis of the high-resolution Siple Dome multivariate ice core chemical time series record (SDEOF1) documents lower tropospheric transport of sea-salt aerosols to the site. During 1985–1994 the SDEOF1 record of high (low) aerosol transport corresponds to anomalously low (high) sea level pressure (SLP) in the Amundsen Sea region. Spatial correlation patterns between ECMWF monthly SLP fields …
Derived Quantities: A Coupled Dynamic/Thermodynamic Ice Sheet Model, James L. Fastook
Derived Quantities: A Coupled Dynamic/Thermodynamic Ice Sheet Model, James L. Fastook
University of Maine Office of Research Administration: Grant Reports
This award is for support for a program of research involving the use of inverse modeling to derive information from the measured configuration of an ice sheet to yield important information about the conditions both at the bed and within the ice column. It is proposed to convert a column-averaged model to a column- integrated model that accounts explicitly for internal thermodynamics and variations of material properties that depend on this internal temperature field. An existing finite-element 3- D temperature solver will be coupled with an existing finite- element map-plane continuity solver. The result will allow more detailed analysis of …
Evidence For Recent Climate Change From Ice Cores In The Central Himalaya, Qin Dahe, Paul Andrew Mayewski, Cameron P. Wake, Kang Shichang, Ren Jiawen, Hou Shugui, Yao Tandong, Yang Qinzhao, Jin Zhefan, Mi Desheng
Evidence For Recent Climate Change From Ice Cores In The Central Himalaya, Qin Dahe, Paul Andrew Mayewski, Cameron P. Wake, Kang Shichang, Ren Jiawen, Hou Shugui, Yao Tandong, Yang Qinzhao, Jin Zhefan, Mi Desheng
Earth Science Faculty Scholarship
Comparison of the terminus locations of Rongbuk Glacier, Mount Everest, measured in 1966 and 1997 shows that in the past 30 years the glacier has retreated 170-270 m, equivalent to a retreat speed of 5.5-8.7 m a−1. During summer 1997, a 15 m firn core was recovered from Dasuopu glacier (28°23′N, 85°44′E; 7000 m a.s.l.) on the northwest margin of Xixabangma Feng, Xizang (Tibet). The seasonal variations of δ18O values in the core indicate that monsoon signals are clearly recorded in the glacier. δ18O values are controlled by the amount effect in the monsoon …
Monsoon And Dust Signals Recorded In Dasuopu Glacier, Tibetan Plateau, Kang Shichang, Cameron P. Wake, Qin Dahe, Paul Andrew Mayewski, Yao Tandong
Monsoon And Dust Signals Recorded In Dasuopu Glacier, Tibetan Plateau, Kang Shichang, Cameron P. Wake, Qin Dahe, Paul Andrew Mayewski, Yao Tandong
Earth Science Faculty Scholarship
During summer 1997, a 15m firn core was recovered from Dasuopu glacier (28°23'N, 85° 44' E; 7000 m a.s.l.) on the northwest margin of Xixabangma Feng in the central Himalaya. Oxygen isotope values and concentrations of Ca2+, Mg2+, NH4+, SO42- and NO3- were measured over the 10 years of snow accumulation captured in the firn core. The seasonal variations of δ18O values and major-ion concentrations in the Dasuopu core indicated that summer monsoon and dust signals are clearly recorded in Dasuopu glacier. Annual variations in the δ …
In Situ Stress Tensor Measured In An Alaskan Glacier, W. Tad Pfeffer, Neil Humphrey, B. Amadei, Joel T. Harper, J. Wegmann
In Situ Stress Tensor Measured In An Alaskan Glacier, W. Tad Pfeffer, Neil Humphrey, B. Amadei, Joel T. Harper, J. Wegmann
Geosciences Faculty Publications
An experimental program at Worthington Glacier, Alaska, U.S.A., has yielded the first in situ measurements of the full stress tensor in glacier ice. Measurements were made with an array of stiff (low-compliance) normal-force sensors frozen into a borehole at 120 m depth. Freezing in temperate ice was accomplished by a down-hole heat exchanger which extracted heat at the rate of 15 W. Under slowly varying stress conditions, relaxation of stress anomalies by viscous creep following drilling of the hole and installation of the sensors allows for equilibration of measured stresses with far-field stresses. Equilibration of local and far-field stresses was …
The Link Between Climate Warming And Break-Up Of Ice Shelves In The Antarctic Peninsula, Ted A. Scambos, Christina L. Hulbe, Mark A. Fahnestock, Jennifer Bohlander
The Link Between Climate Warming And Break-Up Of Ice Shelves In The Antarctic Peninsula, Ted A. Scambos, Christina L. Hulbe, Mark A. Fahnestock, Jennifer Bohlander
Geology Faculty Publications and Presentations
A review of in situ and remote-sensing data covering the ice shelves of the Antarctic Peninsula provides a series of characteristics closely associated with rapid shelf retreat: deeply embayed ice fronts; calving of myriad small elongate bergs in punctuated events; increasing flow speed; and the presence of melt ponds on the ice-shelf surface in the vicinity of the break-ups. As climate has warmed in the Antarctic Peninsula region, melt-season duration and the extent of ponding have increased. Most break-up events have occurred during longer melt seasons, suggesting that meltwater itself, not just warming, is responsible. Regions that show melting without …
Revised Glacial Margins And Wisconsin Meltwater Paleoflood Hydrology In Slippery Rock Creek Basin, Central Western Pennsylvania, Gary John D'Urso
Revised Glacial Margins And Wisconsin Meltwater Paleoflood Hydrology In Slippery Rock Creek Basin, Central Western Pennsylvania, Gary John D'Urso
Graduate Theses, Dissertations, and Problem Reports
Glacial margins mapped in Slippery Rock Creek basin during the 1950s are problematic. The number of sedimentological, mineralogical, petrological, and textural analyses used to distinguish glacial drifts in the southern portion of the basin were inadequate to resolve the margins. Furthermore, misidentification of man-made deposits as glacial drift led to erroneous interpretations regarding the extent and character of pre-Wisconsin glacial deposits, and appears to have influenced subsequent soil mapping. Canadian Shield erratic weathering was the primary tool used in this study to re-investigate the glacial margins. Erratics display one of three distinctive weathering rinds, so glacial deposits can be differentiated …