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Articles 1 - 16 of 16
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The Aeolian Flux Of Calcium, Chloride And Nitrate To The Mcmurdo Dry Valleys Landscape: Evidence From Snow Pit Analysis, Rebecca A. Witherow, W. Berry Lyons, Nancy A.N. Bertler, Kathleen A. Welch, Paul Andrew Mayewski, Sharon B. Sneed, Thomas Nylen, Michael J. Handley, Andrew Fountain
The Aeolian Flux Of Calcium, Chloride And Nitrate To The Mcmurdo Dry Valleys Landscape: Evidence From Snow Pit Analysis, Rebecca A. Witherow, W. Berry Lyons, Nancy A.N. Bertler, Kathleen A. Welch, Paul Andrew Mayewski, Sharon B. Sneed, Thomas Nylen, Michael J. Handley, Andrew Fountain
Earth Science Faculty Scholarship
We have determined the flux of calcium, chloride and nitrate to the McMurdo Dry Valleys region by analysing snow pits for their chemical composition and their snow accumulation using multiple records spanning up to 48 years. The fluxes demonstrate patterns related to elevation and proximity to the ocean. In general, there is a strong relationship between the nitrate flux and snow accumulation, indicating that precipitation rates may have a great influence over the nitrogen concentrations in the soils of the valleys. Aeolian dust transport plays an important role in the deposition of some elements (e.g. C(2+)) into the McMurdo Dry …
The Effects Of Joint Enso-Antarctic Oscillation Forcing On The Mcmurdo Dry Valleys, Antarctica, Nancy A.N. Bertler, T. R. Naish, H. Oerter, S. Kipfstuhl, P. J. Barrett, Paul Andrew Mayewski, Karl J. Kreutz
The Effects Of Joint Enso-Antarctic Oscillation Forcing On The Mcmurdo Dry Valleys, Antarctica, Nancy A.N. Bertler, T. R. Naish, H. Oerter, S. Kipfstuhl, P. J. Barrett, Paul Andrew Mayewski, Karl J. Kreutz
Earth Science Faculty Scholarship
Stable oxygen analyses and snow accumulation rates from snow pits sampled in the McMurdo Dry Valleys have been used to reconstruct variations in summer temperature and moisture availability over the last four decades. The temperature data show a common interannual variability, with strong regional warmings occurring especially in 1984/85, 1995/96 and 1990/91 and profound coolings during 1977/78, 1983/84, 1988/89, 1993/94, and 1996/97. Annual snow accumulation shows a larger variance between sites, but the early 1970s, 1984, 1997, and to a lesser degree 1990/91 are characterized overall by wetter conditions, while the early and late 1980s show low snow accumulation values. …
Satellite Remote Sensing Of Glaciers And Ice Caps In Svalbard, Eurasian High Arctic, Gordon S. Hamilton
Satellite Remote Sensing Of Glaciers And Ice Caps In Svalbard, Eurasian High Arctic, Gordon S. Hamilton
University of Maine Office of Research Administration: Grant Reports
Recent compilations of climate-related observations show that important changes are now underway in the High Arctic, probably as a response to anthropogenic greenhouse gas emissions over the last approximately 250 years. These changes include warming of the troposphere, reductions in sea ice cover, decreases in snow cover area, warming of tundra permafrost, and negative mass balances of glaciers and ice caps. In many instances, observations of change are relatively short in duration or sparse in spatial extent. The Principal Investigators will study glacier and ice cap variations over the approximately last 80 years and at a large scale on Svalbard. …
Collaborative Research: The Tectonothermal Evolution Of A Convergent Orogen, Scott E. Johnson
Collaborative Research: The Tectonothermal Evolution Of A Convergent Orogen, Scott E. Johnson
University of Maine Office of Research Administration: Grant Reports
Understanding of orogenesis and its relations to mantle convection and plate tectonics relies on integrated studies of the interrelations among processes of deformation, metamorphism and magmatism. A well preserved portion of the northern Appalachian orogen is providing an outstanding laboratory for a truly integrative study of the evolution of mid-crustal processes that strongly influence orogenesis. This project is employing structural, microstructural, petrologic and thermobarometric analyses, and chemical and isotopic dating, to temporally and spatially link deformation, metamorphism and magmatism during the progressive growth of this orogenic belt. This information is being used to set constraints and boundary conditions on coupled, …
An Aquaculture-Based Method For Calibrated Bivalve Isotope Paleothermometry, Alan D. Wanamaker Jr., Karl J. Kreutz, Harold W. Borns Jr., Douglas S. Introne, Scott Feindel, Bruce J. Barber
An Aquaculture-Based Method For Calibrated Bivalve Isotope Paleothermometry, Alan D. Wanamaker Jr., Karl J. Kreutz, Harold W. Borns Jr., Douglas S. Introne, Scott Feindel, Bruce J. Barber
Earth Science Faculty Scholarship
To quantify species- specific relationships between bivalve carbonate isotope geochemistry ( delta O-18(c)) and water conditions ( temperature and salinity, related to water isotopic composition [delta O-18(w)]), an aquaculture-based methodology was developed and applied to Mytilus edulis ( blue mussel). The four- by- three factorial design consisted of four circulating temperature baths ( 7, 11, 15, and 19 degrees C) and three salinity ranges ( 23, 28, and 32 parts per thousand ( ppt); monitored for delta O-18(w) weekly). In mid- July of 2003, 4800 juvenile mussels were collected in Salt Bay, Damariscotta, Maine, and were placed in each configuration. …
Calving Giant Icebergs: Old Principles, New Applications, James P. Kenneally, Terence J. Huges
Calving Giant Icebergs: Old Principles, New Applications, James P. Kenneally, Terence J. Huges
Earth Science Faculty Scholarship
Earth-orbiting satellites can now monitor calving of large icebergs from ice shelves bordering the marine West Antarctic Ice Sheet, and recent calving events have stimulated interest in calving mechanisms. To advance this interest pioneering work in brittle and ductile fracture mechanics is reviewed, leading to a new application to calving of giant icebergs from Antarctic ice shelves. The aim is to view iceberg calving as more than terminal events for Antarctic ice when glaciologists lose interest. Instead calving launches Antarctic ice into the larger dynamic system of Earth's climate machine. This encourages a holistic approach to glaciology.
Antarctic Temperatures Over The Past Two Centuries From Ice Cores, David P. Schneider, Eric J. Steig, Tas D. Van Ommen, Daniel A. Dixon, Paul Andrew Mayewski, Julie M. Jones, Cecilia M. Bitz
Antarctic Temperatures Over The Past Two Centuries From Ice Cores, David P. Schneider, Eric J. Steig, Tas D. Van Ommen, Daniel A. Dixon, Paul Andrew Mayewski, Julie M. Jones, Cecilia M. Bitz
Earth Science Faculty Scholarship
We present a reconstruction of Antarctic mean surface temperatures over the past two centuries based on water stable isotope records from high-resolution, precisely dated ice cores. Both instrumental and reconstructed temperatures indicate large interannual to decadal scale variability, with the dominant pattern being anti-phase anomalies between the main Antarctic continent and the Antarctic Peninsula region. Comparative analysis of the instrumental Southern Hemisphere (SH) mean temperature record and the reconstruction suggests that at longer timescales, temperatures over the Antarctic continent vary in phase with the SH mean. Our reconstruction suggests that Antarctic temperatures have increased by about 0.2 degrees C since …
Ice Core Evidence For A Second Volcanic Eruption Around 1809 In The Northern Hemisphere, Kaplan Yalcin, Cameron P. Wake, Karl J. Kreutz, Mark S. Germani, Sallie I. Whitlow
Ice Core Evidence For A Second Volcanic Eruption Around 1809 In The Northern Hemisphere, Kaplan Yalcin, Cameron P. Wake, Karl J. Kreutz, Mark S. Germani, Sallie I. Whitlow
Earth Science Faculty Scholarship
A volcanic signal observed in ice cores from both polar regions six years prior to Tambora is attributed to an unknown tropical eruption in 1809. Recovery of dacitic tephra from the 1809 horizon in a Yukon ice core ( Eclipse) that is chemically distinct from andesitic 1809 tephra found in Antarctic ice cores indicates a second eruption in the Northern Hemisphere at this time. Together with the similar magnitude and timing of the 1809 volcanic signal in the Arctic and Antarctic, this could suggest a large tropical eruption produced the sulfate and Antarctic tephra and a minor Northern Hemisphere eruption …
The 1452 Or 1453 A.D. Kuwae Eruption Signal Derived From Multiple Ice Core Records: Greatest Volcanic Sulfate Event Of The Past 700 Years, Chaochao Gao, Alan Robock, Stephen Self, Jeffrey B. Witter, J. P. Steffenson, Henrik Brink Clausen, Marie-Louise Siggard-Andersen, Sigfus Johnson, Paul Andrew Mayewski, Caspar Ammann
The 1452 Or 1453 A.D. Kuwae Eruption Signal Derived From Multiple Ice Core Records: Greatest Volcanic Sulfate Event Of The Past 700 Years, Chaochao Gao, Alan Robock, Stephen Self, Jeffrey B. Witter, J. P. Steffenson, Henrik Brink Clausen, Marie-Louise Siggard-Andersen, Sigfus Johnson, Paul Andrew Mayewski, Caspar Ammann
Earth Science Faculty Scholarship
We combined 33 ice core records, 13 from the Northern Hemisphere and 20 from the Southern Hemisphere, to determine the timing and magnitude of the great Kuwae eruption in the mid-15th century. We extracted volcanic deposition signals by applying a high-pass loess filter to the time series and examining peaks that exceed twice the 31 year running median absolute deviation. By accounting for the dating uncertainties associated with each record, these ice core records together reveal a large volcanogenic acid deposition event during 1453 - 1457 A. D. The results suggest only one major stratospheric injection from the Kuwae eruption …
A 12,000 Year Record Of Explosive Volcanism In The Siple Dome Ice Core, West Antarctica, Andrei V. Kurbatov, G. A. Zelinski, N. W. Dunbar, Paul Andrew Mayewski, E. A. Meyerson, Sharon B. Sneed, K. C. Taylor
A 12,000 Year Record Of Explosive Volcanism In The Siple Dome Ice Core, West Antarctica, Andrei V. Kurbatov, G. A. Zelinski, N. W. Dunbar, Paul Andrew Mayewski, E. A. Meyerson, Sharon B. Sneed, K. C. Taylor
Earth Science Faculty Scholarship
Air mass trajectories in the Southern Hemisphere provide a mechanism for transport to and deposition of volcanic products on the Antarctic ice sheet from local volcanoes and from tropical and subtropical volcanic centers. This study extends the detailed record of Antarctic, South American, and equatorial volcanism over the last 12,000 years using continuous glaciochemical series developed from the Siple Dome A (SDMA) ice core, West Antarctica. The largest volcanic sulfate spike ( 280 mu g/L) occurs at 5881 B. C. E. Other large signals with unknown sources are observed around 325 B. C. E. ( 270 mu g/L) and 2818 …
Numerical Facility In Geodynamics, Peter O. Koons, Scott Johnson, Phaedra Upton
Numerical Facility In Geodynamics, Peter O. Koons, Scott Johnson, Phaedra Upton
University of Maine Office of Research Administration: Grant Reports
Support from this grant will contribute to the construction of a numerical facility for Geodynamical Modeling at the University of Maine to investigate mechanical and thermal problems arising in lithosphere and mantle deformation. Specifically, the PI's will examine the degree of coupling among atmospheric and tectonic processes through construction of three-dimensional models conditioned by observations from the active tectonic regions of eastern Tibet, New Zealand and southeast Alaska. In related research, the PI's are examining the necessary conditions for formation and exhumation of ultra-high pressure metamorphism terrains during plate convergence. The overriding objective of the numerical facility is to provide …
Governance And The Capacity To Manage Resilience In Regional Social-Ecological Systems, Louis Lebel, John M. Anderies, Bruce Campbell, Carl Folke, Steve Hatfield-Dodds, Terence P. Hughes, James Wilson
Governance And The Capacity To Manage Resilience In Regional Social-Ecological Systems, Louis Lebel, John M. Anderies, Bruce Campbell, Carl Folke, Steve Hatfield-Dodds, Terence P. Hughes, James Wilson
Earth Science Faculty Scholarship
The sustainability of regional development can be usefully explored through several different lenses. In situations in which uncertainties and change are key features of the ecological landscape and social organization, critical factors for sustainability are resilience, the capacity to cope and adapt, and the conservation of sources of innovation and renewal. However, interventions in social-ecological systems with the aim of altering resilience immediately confront issues of governance. Who decides what should be made resilient to what? For whom is resilience to be managed, and for what purpose? In this paper we draw on the insights from a diverse set of …
A New Mt. Logan Ice Core Record - Change In Climate And Chemistry Of The Atmosphere For The North Pacific, Paul Andrew Mayewski, Gregory Zielinski, Karl J. Kreutz, Andrei V. Kurbatov
A New Mt. Logan Ice Core Record - Change In Climate And Chemistry Of The Atmosphere For The North Pacific, Paul Andrew Mayewski, Gregory Zielinski, Karl J. Kreutz, Andrei V. Kurbatov
University of Maine Office of Research Administration: Grant Reports
Mt. Logan, in the St. Elias Range, southeast Alaska, offers a unique opportunity for monitoring climate change and change in the atmospheric chemistry of the Gulf of Alaska and the North Pacific. In 1980, a 103-meter (M) ice core was recovered from Mt. Logan which spanned AD 1689-1980. It revealed well-defined annual layers, calibrated through the identification of radioactive bomb and volcanic horizons, allowing continuous, sub-seasonal sampling for stable isotopes and ion chemistry. The -29 degree C mean annual temperature at the site assures that the soluble, insoluble, and isotopic components of the core are well preserved.
In 2001 and …
Glaciology Of Blue Ice Areas In Antarctica, Gordon Hamilton
Glaciology Of Blue Ice Areas In Antarctica, Gordon Hamilton
University of Maine Office of Research Administration: Grant Reports
A 'horizontal ice core' was collected at the Mount Moulton blue ice field in West Antarctica and preliminary analyses of the sample material suggests that a ~500 kyr climate record is preserved in the ice at this site. This award will contribute to the understanding of the Mt Moulton record by assessing the potential for ice-flow induced deformation of the stratigraphic profile. In addition, this award builds on the recognition of blue ice areas as archives of long climate records by conducting reconnaissance studies for a potential horizontal ice core location at the Allan Hills in East Antarctica. The objectives …
Mass Balance And Accumulation Rate Along Us Itase Routes, Gordon Hamilton
Mass Balance And Accumulation Rate Along Us Itase Routes, Gordon Hamilton
University of Maine Office of Research Administration: Grant Reports
The primary research activities in this project involved our participation in the four US ITASE field seasons (1999-2003). As part of the field program we collected ~5,500 km of continuous, precise GPS data along the traverse route. These geodetic data are used by ourselves and several other US ITASE investigators. We also installed 15 new mass balance (coffee can) stations in rarely visited regions of West and East Antarctica. Several shallow firn cores were collected to study local variability in snow accumulation around deeper 200-year ice core sites. As part of our collaboration with NASA, we performed detailed 3-dimensional mapping …
A Science Management Office For The U. S. Component Of The International Trans Antarctic Expedition (Us Itase Smo)Ûa Collaborative Pgrm Of Research From S. Pole To N. Victoria Land, Paul A. Mayewski, Gordon S. Hamilton
A Science Management Office For The U. S. Component Of The International Trans Antarctic Expedition (Us Itase Smo)Ûa Collaborative Pgrm Of Research From S. Pole To N. Victoria Land, Paul A. Mayewski, Gordon S. Hamilton
University of Maine Office of Research Administration: Grant Reports
This award supports a science management office for a pilot ice-core drilling and analysis program to test the feasibility of obtaining well-dated, high-resolution isotope and chemistry records from East Antarctica. Shallow ice cores will be obtained from two locations: 1) ~100 km from South Pole towards the Pole of Inaccessibility, as an extension of the Byrd Station-to-South Pole ITASE traverse [International Trans Antarctic Scientific Expedition]; 2) at Taylor Dome, near the original deep coring site, and (3) possibly at AGO 3 and AGO 4 as part of a logistics traverse to these sites. All of the cores collected will be …