Open Access. Powered by Scholars. Published by Universities.®

Glaciology Commons™

Open Access. Powered by Scholars. Published by Universities.®

2002

Articles 1 - 12 of 12

Full-Text Articles in Glaciology

Formation And Age Of Raised Marine Beaches, Northern Scott Coast, Antarctica, Nathan Gardner Dec 2002

Formation And Age Of Raised Marine Beaches, Northern Scott Coast, Antarctica, Nathan Gardner

Electronic Theses and Dissertations

The stability of the West Antarctic Ice Sheet (WAIS) is a key problem because of its potential effect on global sea level and climate. Some geologic evidence suggests that the ice sheet has collapsed in the past, which, if correct, implies that future disintegration is possible. Isolation of the mechanism(s) that have affected WAIS behavior since the last glacial maximum (LGM) may yield information about factors that control it today. Previous studies have indicated thatrecession of the WAIS from the LGM position occurred in the middle to late Holocene. However, the data come fiom points too far south to assess …

Go to article

A 700-Year Record Of Atmospheric Circulation Developed From The Law Dome Ice Core, East Antarctica, Joseph M. Souney Jr, Paul A. Mayewski, Ian D. Goodwin, David Meeker, Vin Morgan, Mark Aj Curran, Tas D. Van Ommen, Anne S. Palmer Nov 2002

A 700-Year Record Of Atmospheric Circulation Developed From The Law Dome Ice Core, East Antarctica, Joseph M. Souney Jr, Paul A. Mayewski, Ian D. Goodwin, David Meeker, Vin Morgan, Mark Aj Curran, Tas D. Van Ommen, Anne S. Palmer

Earth Systems Research Center

A 700-year, high-resolution, multivariate ice core record from Dome Summit South (DSS) (66°46′S, 112°48′E; 1370 m), Law Dome, is used to investigate sea level pressure (SLP) variability in the region of East Antarctica. Empirical orthogonal function (EOF) analysis reveals that the first EOF (LDEOF1) of the combined glaciochemical, oxygen isotope ratio, and accumulation rate record from DSS represents most of the variability in sea salt seen in the record. LDEOF1 is positively correlated (at least 95% confidence level) to instrumental June mean SLP across most of East Antarctica. Over the last 700 years, LDEOF1 levels at Law Dome were the …

Go to article

A New Ice Core From The Devon Ice Cap Canadian Arctic: Continued Development Of High-Resolution Proxy Records To Evaluate The Regionalization Of Climate In The Circum-Arctic, George A. Zielinski, Cameron Wake Sep 2002

A New Ice Core From The Devon Ice Cap Canadian Arctic: Continued Development Of High-Resolution Proxy Records To Evaluate The Regionalization Of Climate In The Circum-Arctic, George A. Zielinski, Cameron Wake

University of Maine Office of Research Administration: Grant Reports

The primary goal of this project was to collect an ice core from the Summit of the Devon Ice Cap, Devon Island, Canadian Arctic. A 302-m core was collected during the spring of 1998 with additional field work in 1999. Individuals supported by this grant participated in the field work, although the GSC did the actual drilling. Glacier flow models as well as physical characteristics of the ice and d18O records suggest that basal ice recovered is about 86,000 years old. The first 200 meters were collected under dry drilling conditions, whereas the final 52 meters were collected with a …

Go to article

Examination Of The 500,000-Year Climate Record In Ice At Mt. Moulton, West Antarctica, Gregory A. Zielinski, Paul Andrew Mayewski Sep 2002

Examination Of The 500,000-Year Climate Record In Ice At Mt. Moulton, West Antarctica, Gregory A. Zielinski, Paul Andrew Mayewski

University of Maine Office of Research Administration: Grant Reports

This project was a pilot project to determine if the ice on Mt. Moulton provides a reliable record of past climatic conditions. The area of study is a several hundred-meter section of blue ice (Trench A) that spans the time period from approximately the early Holocene to over 492k years ago. Dating control is obtained through radiometrically-dated tephra layers (i.e., air fall deposits) within the section (Figure 1) originating from the adjacent Mt. Berlin. Fieldwork during the 1999-2000 field season included the trenching of the complete section with electric chain saws mounted on a wheeled frame. Blocks were extracted and …

Go to article

(Esh) Holocene Climate Variability, Paul Andrew Mayewski, Loreen Meeker Aug 2002

(Esh) Holocene Climate Variability, Paul Andrew Mayewski, Loreen Meeker

University of Maine Office of Research Administration: Grant Reports

With the successful completion of deep drilling at Summit Greenland there is now a well-dated, high resolution, multi-parameter record of climate change (response and forcing) for the Northern Hemisphere that covers the last glacial cycle. This record reveals evidence of rapid and dramatic change in climate. Recent examination of the Holocene portion (last 11,500 years) of the Greenland record has demonstrated that, while relatively stable by comparison with glacial age climate, the Holocene does contain subdued versions of glacial age millennial scale and rapid climate change events. The Holocene is also characterized by significant annual to centennial scale variability plus …

Go to article

Late Holocene Sea-Level Change Around Newfoundland, Julia Daly Aug 2002

Late Holocene Sea-Level Change Around Newfoundland, Julia Daly

Electronic Theses and Dissertations

Analysis of basal salt-marsh peats and tide-gauge data from several locations around Newfoundland yield high-resolution late Holocene sea-level reconstructions and constrain differential sea-level change. The transition between rising and falling local sea levels and the influence of glacioisostasy on relative sea-level change around Newfoundland through the late Holocene are not well known fiom previous research. The patterns of local relative sea-level change during this time have important implications for constraining numerical models of sea-level change, and therefore inferences about ice sheet thickness and the response of the lithosphere to deglaciation. I investigated the stratigraphy of salt marshes at four locations …

Go to article

A Finite-Element Model Of Basal Water Generated By Melting In An Ice Sheet Model, James L. Fastook May 2002

A Finite-Element Model Of Basal Water Generated By Melting In An Ice Sheet Model, James L. Fastook

University of Maine Office of Research Administration: Grant Reports

It is well known that water is produced at the bed of an ice sheet when the temperature of the bed reaches the pressure melting point. The current ice sheet model, with its ability to calculate temperatures throughout the ice sheet, is also able to calculate melt rates at the bed. By incorporating a model of the continuity equation for the basal-water flow, this project will attempt to follow the movement of this water under the ice sheet as it flows from source regions to sink regions. The ability to predict wet-based regions is important to the understanding of the …

Go to article

Distribution Of Patterned Ground And Surficial Deposits On A Debris-Covered Glacier Surface In Mullins Valley And Upper Beacon Valley, Antarctica, Andrew M. Lorrey May 2002

Distribution Of Patterned Ground And Surficial Deposits On A Debris-Covered Glacier Surface In Mullins Valley And Upper Beacon Valley, Antarctica, Andrew M. Lorrey

Electronic Theses and Dissertations

Beacon Valley is located in the western Dry Valleys, Antarctica, adjacent to the East Antarctic Ice Sheet (EAIS). The surficial material on the floor of Beacon Valley is segmented into large polygonal landforms separated by trenches. Buried beneath the polygons and surficial material is massive ground ice. One hypothesis is that the buried ice in upper Beacon Valley is glacier ice originating from local debris-covered glaciers. The networks of polygons and trenches form as the buried ice undergoes thermal contraction and sublimation. Contraction cracks that penetrate the surficial material and buried ice in Beacon Valley contain Late Miocene age volcanic …

Go to article

Siple Dome Deep Ice Core Glaciochemistry And Regional Survey - A Contribution To The Wais Initiative, Paul Andrew Mayewski, Loren D. Meeker Apr 2002

Siple Dome Deep Ice Core Glaciochemistry And Regional Survey - A Contribution To The Wais Initiative, Paul Andrew Mayewski, Loren D. Meeker

University of Maine Office of Research Administration: Grant Reports

Our project focuses on the analysis and interpretation of major ions and methanesulfonate (in conjunction with the Univ. of Miami) from a deep ice core at Siple Dome, Antarctica. In addition, this study investigates the regional glaciochemical variability on Siple Dome, continuing work begun during the 1994 field season. The first field season for this project was conducted during the 1996/97 austral season. Because this project closely follows work begun in 1994, selected glaciochemical results from 1994 are presented, along with reports that detail Siple Dome research to present.

Go to article

Transition From Contraction To Extension In The Northeastern Basin And Range: New Evidence From The Copper Mountains, Nevada, Jeffrey M. Rahl, Allen J. Mcgrew, Kenneth A. Foland Mar 2002

Transition From Contraction To Extension In The Northeastern Basin And Range: New Evidence From The Copper Mountains, Nevada, Jeffrey M. Rahl, Allen J. Mcgrew, Kenneth A. Foland

Geology Faculty Publications

New mapping, structural analysis, and 40Ar/39Ar dating reveal an unusually well‐constrained history of Late Eocene extension in the Copper Mountains of the northern Basin and Range province. In this area, the northeast‐trending Copper Creek normal fault juxtaposes a distinctive sequence of metacarbonate and granitoid rocks against a footwall of Upper Precambrian to Lower Cambrian quartzite and phyllite. Correlation of the hanging wall with footwall rocks to the northwest provides an approximate piercing point that requires 8–12 km displacement in an ESE direction. This displaced fault slice is itself bounded above by another normal fault (the Meadow Fork Fault), which brings …

Go to article

Chemical Composition Of Fresh Snow On Xixabangma Peak, Central Himalaya, During The Summer Monsoon Season, Shichang Kang, Dahe Qin, Paul Andrew Mayewski, Sharon B. Sneed Jan 2002

Chemical Composition Of Fresh Snow On Xixabangma Peak, Central Himalaya, During The Summer Monsoon Season, Shichang Kang, Dahe Qin, Paul Andrew Mayewski, Sharon B. Sneed

Earth Science Faculty Scholarship

The physical and chemical analysis of ice cores recovered from glaciers in the Himalaya provide some of the best records of past climate change in the region (e.g. Qin and others, 2000; Thompson and others, 2000; Kang and others, 2001, 2002). In order to better understand the climatic and environmental records preserved in snow and ice, studies have investigated the precipitation chemistry in the high Himalaya, notably that the northern slopes of the central Himalaya (Mayewski and others, 1986; Jenkins and others 1987) and the southern slopes of the central Himalaya (Shrestha and others, 1997; Marinoni and others, 2001).

Go to article

Basal Conditions And Glacier Motion During The Winter/Spring Transition, Worthington Glacier, Alaska, U.S.A., Joel T. Harper, Neil Humphrey, Mark C. Greenwood Jan 2002

Basal Conditions And Glacier Motion During The Winter/Spring Transition, Worthington Glacier, Alaska, U.S.A., Joel T. Harper, Neil Humphrey, Mark C. Greenwood

Geosciences Faculty Publications

Observations of the motion and basal conditions of Worthington Glacier, Alaska, U.S.A., during late-winter and spring melt seasons revealed no evidence of a relationship between water pressure and sliding velocity. Measurements included borehole water levels (used as a proxy for basal water pressure), surface velocity, englacial deformation, sliding velocity, and time-lapse videography of subglacial water flow and bed characteristics. The boreholes were spaced 10-15 m apart; six were instrumented in 1997, and five in 1998. In late winter, the water-pressure field showed spatially synchronous fluctuations with a diurnal cycle. The glacier's motion was relatively slow and non-cyclic. In spring, the …

Go to article