Physical Sciences and Mathematics Commons^™

Collaborative Research: Origins Of Cods On Georges Bank: Contributions Of Early Developmental Stages For The Scotian Shelf, David W. Townsend, Irv Kornfield, Linda Kling

University of Maine Office of Research Administration: Grant Reports

Recent work in the Georges Bank-Gulf of Maine area has documented significant, and apparently episodic, fluxes of Scotian Shelf Water (SSW) from the Nova Scotian continental shelf to Georges Bank. SSW is a relatively cold and fresh water mass with a significant component from the St. Lawrence River, and is commonly identifiable with temperature-salinity analyses of hydrographic data and in satellite images of sea surface temperature. One such flux episode was observed last March (1997) in satellite imagery and from shipboard hydrographic sampling on Georges Bank. Qualitative at-sea analyses of ichthyoplankton sampled on the March cruise revealed a remarkably tight …

Surface "Waves" On Byrd Glacier, Antarctica, D. Reusch, Terence J. Hughes

Earth Science Faculty Scholarship

Byrd Glacier has one of the largest ice catchment areas in Antarctica, delivers more ice to the Ross Ice Shelf than any other ice stream, and is the fastest of these ice streams. A force balance, combined with a mass balance, demonstrates that stream flow in Byrd Glacier is transitional from sheet flow in East Antarctica to shelf flow in the Ross Ice Shelf. The longitudinal pulling stress, calculated along an ice flowband from the force balance, is linked to variations of ice thickness, to the ratio of the basal water pressure to the ice overburden pressure where Byrd Glacier …

Ams Radiocarbon Chronology Of Glacier Fluctuations In The South Shetland Islands During The Last Glacial/Interglacial Hemicycle:Implications For Global Climate Change, Brenda L. Hall

University of Maine Office of Research Administration: Grant Reports

This award supports a two year program to produce a new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum (LGM) for the South Shetland Islands in the Antarctic Peninsula. One field season on Livingston Island will involve mapping the areal extent and geomorphology of glacial drift and determining the elevation and distribution of trimlines. In addition, ice flow direction will be determined by mapping and measuring the elevation of erosional features and the position of erratic boulders. One of the main goals of this work will be to demonstrate whether or not organic material suitable for …

Extension And Partitioning In An Oblique Subduction Zone, New Zealand: Constraints From Three-Dimensional Numerical Modeling, Phaedra Upton, Peter O. Koons, Donna Eberhart-Phillips

Earth Science Faculty Scholarship

Contraction, strike slip, and extension displacements along the Hikurangi margin northeast of the North Island of New Zealand coincide with large lateral gradients in material properties. We use a finite- difference code utilizing elastic and elastic-plastic rheologies to build large- scale, three-dimensional numerical models which investigate the influence of material properties on velocity partitioning within oblique subduction zones. Rheological variation in the oblique models is constrained by seismic velocity and attenuation information available for the Hikurangi margin. We compare the effect of weakly versus strongly coupled subduction interfaces on the development of extension and the partitioning of velocity components for …

Geometrical Force Balance In Glaciology, Terence J. Hughes

Earth Science Faculty Scholarship

The analytical force balance traditionally used in glaciology relates gravitational forcing to ice surface slope for sheet flow and to ice basal buoyancy for shelf flow. It is unable to represent stream flow as a transition from sheet flow to shelf flow by having gravitational forcing gradually passing from being driven by surface slope to being driven by basal buoyancy downslope along the length of an ice steam. This is a serious defect, because ice streams discharge up to 90% of ice from ice sheets into the sea. The defect is overcome by using a geometrical force balance that includes …

Prismatine And Ferrohogbomite-2n2s In Granulite-Facies Fe-Oxide Lenses In The Eastern Ghats Belt At Venugopalapuram, Vizianagaram District, Andhra Pradesh, India: Do Such Lenses Have A Tourmaline-Enriched Lateritic Precursor?, Edward S. Grew, A. T. Rao, K.K. V.S. Raju, C. Hejny, J. M. Moore, D. J. Waters, Martin G. Yates, C. K. Shearer

Earth Science Faculty Scholarship

Fluorine-rich prismatine, (square,Fe,Mg)(Mg,Al,Fe)(5)Al-4(Si,B,Al)(5)O-21(OH,F), with F/(OH+F) = 0.36-0.40 and hercynite are major constituents of a Fe-Al-B-rich lens in ultrahigh-temperature granulite-facies quartz-sillimanite-hypersthene-cordierite gneisses of the Eastern Ghats belt, Andhra Pradesh, India. Hemo-ilmenite. sapphirine, magnetite, biotite and sillimanite are subordinate. Lithium, Be and B are concentrated in prismatine (140 ppm Li, 170 ppm Be, and 2.8-3.0 wt.% B2O3). Another Fe-rich lens is dominantly magnetite, which encloses fine-grained zincian ferrohogbomite-2N2S, (Fe2+ Mg,Zn,Al)(6) (Al,Fe3+,Ti)(16)O-30(OH)(2), containing minor Ga2O3 (0.30-0.92 wt.%). Fe-Al-B-rich lenses with prismatine (or kornerupine) constitute a distinctive type of B-enrichment in granulite-facies rocks and have been reported from four other localities worldwide. A scenario …

Organic Coatings On Sedimentary Mineral Grains, Lawrence M. Mayer

University of Maine Office of Research Administration: Grant Reports

A pore protection hypothesis will be tested, provide a mechanistic basis for the observed patterns of organic carbon. Relationships between organic matter and mineral surfaces will be developed by: (1) Assessing the extent of organic matter coverage on mineral grains. Is organic carbon localized in small areas or is it widely dispersed? Wide dispersal implies that major fraction must reside in small pores. This question will be tested by completing development of a promising new method based on the of gas adsorption onto mineral surfaces. Completion work will focus on the nature of naked mineral surfaces, identifying variations that derive …

Mri: Acquisition Of A Modern Electron Microprobe At The University Of Maine, Charles V. Guidotti

University of Maine Office of Research Administration: Grant Reports

This award, made through the Major Research Instrumentation (MRI) Program, provides support for the acquisition of a state-of-the-art electron microprobe (EMP) for the microchemical characterization of geological materials. A new EMP will replace an aging (vintage 1981) ARL SEMQ in the Department of Geological Sciences at the University of Maine. The instrument will facilitate research on a range of topics in metamorphic petrology including, the speciation of Fe and distribution of OH- in metapelites, and light element (i.e. Li, B, Be) partitioning in granulite facies rocks. Research in paleoclimatology will also be enhanced by this instrument. The probe will be …

Seasonal Deuterium Excess In A Tien Shan Ice Core: Influence Of Moisture Transport And Recycling In Central Asia, Karl J. Kreutz, Cameron P. Wake, Vladimir B. Aizen, L. Dewayne Cecil, Hans-Arno Synal

Earth Science Faculty Scholarship

Stable water isotope (delta(18)O, deltaD) data from a high elevation (5100 masl) ice core recovered from the Tien Shan Mountains, Kyrgyzstan, display a seasonal cycle in deuterium excess (d = deltaD - 8* delta(18)O) related to changes in the regional hydrologic cycle during 1994 - 2000. While there is a strong correlation (r(2) = 0.98) between delta(18)O and dD in the ice core samples, the regression slope (6.9) and mean d value (23.0) are significantly different than the global meteoric water line values. The resulting time-series ice core d profile contains distinct winter maxima and summer minima, with a yearly …

Collaborative Research: Volcanic Records From The Siple And Taylor Dome Ice Cores, Antarctica, George A. Zielinski

University of Maine Office of Research Administration: Grant Reports

The primary goals of this project were to, 1) evaluate the volcanic acidity record in the Siple Dome A (SDMA) and B (SDMB) ice cores and the Taylor Dome ice core available through the sulfate time series developed by the glaciochemistry group at the University of Maine, 2) undertake a continuous scan of the SDMA core and scan specific sections in the SDMB core to locate and analyze volcanic glass to determine glass composition, and thus source eruptions for the glass and potentially for volcanic sulfate found in the same layer, and 3) evaluate specific sections containing volcanic glass in …

Antarctic Oversnow Traverse-Based Southern Hemisphere Climate Reconstruction, Paul Andrew Mayewski

Earth Science Faculty Scholarship

On 2 January 2003, the U.S. component of the International Trans Antarctic Scientific Expedition (U.S. ITASE) (Figure 1) arrived at the South Pole after completing more than 5000 km of oversnow traverses that included much of west Antarctica and a portion of east Antarctica (Figure 2). During the traverses, which were performed from 1999 through 2003, U.S. ITASE focused on collecting data that will allow the reconstruction of sub-annual scale climate variability and changes in the chemistry of the atmosphere over the last 200+ years.

ITASE is a multi-disciplinary research program supported by 19 nations and endorsed by the Scientific …

The Response Of A Small Stream In The Lesni Potok Forested Catchment, Central Czech Republic, To A Short-Term In-Stream Acidification, T. Navrátil, M. Vach, Stephen A. Norton, P. Skrivan, J. Hruška, L. Maggini

Earth Science Faculty Scholarship

Lesni Potok stream drains a forested headwater catchment in the central Czech Republic. It was artificially acidified with hydrochloric acid (HCl) for four hours to assess the role of stream substrate in acid-neutralisation and recovery. The pH was lowered from 4.7 to 3.2. Desorption of Ca and MP and desorption or solution of Al dominated acid-neutralisation; Al mobilisation was more important later. The stream substrate released 4.542 meq Ca, 1, 184 meq Mg, and 2,329 meq Al over a 45 in long and I in wide stream segment, smaller amounts of Be. Cd, Fe, and Mn were released. Adsorption of …

Collaborative Research: Did The Laurentine Ice Sheet Control Abrupt Climate Change?, Terence J. Hughes, James L. Fastook, David Bromwich, E. Richard Toracinta

University of Maine Office of Research Administration: Grant Reports

This is a collaborative project with the University of Maine and Ohio State University. The Principal Investigators will model the late glacial Laurentide Ice Sheet from near steady-state equilibrium at - 25,000 BP (years before present), through reversible stadial/interstadial transitions associated with Laurentide iceberg outbursts (Heinrich events 2 and 1), and across the threshold of irreversible Laurentide collapse after the last iceberg outburst at - 1 1,000 BP (Heinrich event 0). The goals are to determine if ice-sheet changes could have triggered climate changes by abrupt ice sheet change and to investigate the structure of these changes. The Principal Investigators …

Discovering Properties Of Complex Numbers By Starting With Known Properties Of Real Numbers, Esther D. Hatch

Honors College

No abstract provided.

Science Management For The United States Component Of The International Trans-Antarctic Expedition, Paul Mayewski

University of Maine Office of Research Administration: Grant Reports

US ITASE is effectively a polar research vessel. It offers the ground-based opportunities of traditional style traverse travel coupled with the modern technology of GPS, crevasse detecting radar, satellite communications and multi-disciplinary research. By operating as a ground-based transport system US ITASE offers scientists the opportunity to experience the dynamic environment they are studying. US ITASE also offers an important interactive venue for research (currently eleven integrated science projects) similar to that afforded by oceanographic research vessels and large polar field camps, without the cost of the former or the lack of mobility of the latter. More importantly the combination …

Proteins Of Oxygen-Binding And Energy Metabolism In Muscles Of Antarctic Fishes: Evolutionary Adjustments To Life At Cold Temperature, Bruce Sidell, Michael E. Vayda

University of Maine Office of Research Administration: Grant Reports

The suborder Notothenoidei is the dominant fish group of the Southern Ocean surrounding Antarctica, both in terms of number of species and biomass. For about fourteen million years, these highly successful fish evolved under stable thermal conditions that result in body temperatures of about zero degrees centigrade throughout their life histories. Evolution this cold environment has led to unusual physiological and biochemical characteristics. In some cases, the characteristics contribute to overcoming constraints of cold temperature on biological processes. In other instances, mutations that probably would have been lethal in warmer, less oxygen-rich environments than the Southern Ocean have been retained …

Control Of Denitrification In A Permanently Ice Covered Antarctic Lake: Potential For Regulation By Bioactive Metals, Mark Wells

University of Maine Office of Research Administration: Grant Reports

Lake Bonney is a permanently ice-covered lake in the Dry ValleyÆs region of Antarctica separated into two deep lobes by a shallow (12 m) sill. Denitrification occurs in the sub-oxic, saline waters of the west lobe but not in that of the east lobe for reasons unknown. Previous work has established this disparity cannot be attributed to temperature or salinity limitations, nor by the comparative availability of organic carbon substrates. Our research objective is to determine if trace metal limitation or toxicity may be responsible for this unusual feature. The broader objective is to assess the likelihood that denitrification in …

Studying Byrd Glacier As A Rock-Floored Ice Stream Ending As A Calving Ice Shelf: Phase I, Terence J. Huges, Roger Hooke, James Fastook

University of Maine Office of Research Administration: Grant Reports

This award supports a one-year study of the floating part of Byrd Glacier, from its grounding line located halfway up a fjord through the Transantarctic Mountains to the end of its lateral rift zone on the Ross Ice Shelf beyond the fjord. Over this l00 km distance, the side boundary changes from rigid between the fjord sidewalls, to nearly free in the lateral rift zone, to deforming when the rifts are healed and Bryd Glacier becomes fully coupled to the Ross Ice Shelf. The stress field for these changing conditions will be calculated a using a gridpoint finite-element model for …

Biodiversity And Ecosystem Informatics: Event And Process Tagging For Information Integration For The International Gulf Of Main Watershed, Mary-Kate Beard-Tisdale, Neal Pettigrew, Jeffrey Kahl, Malcolm L. Hunter Jr., Marilyn Lutz

University of Maine Office of Research Administration: Grant Reports

This incubation proposal addresses the issue of integrating large, diverse, and autonomous collections of scientific data within a complex institutional setting. The goal is to convert these autonomous collections into a shareable repository that supports synthesis of data through new metadata structures based on events and processes. The institutional setting is the data and data-gathering activities of over 80 agencies, NGOS, and academic and research institutions operating within the Gulf of Maine watershed. The metadata development will be coordinated by library and spatial information scientists working jointly with domain scientists. An essential task of this incubation effort will be the …

Buckling Rate And Overhang Development At A Calving Face, Brian Hanson, Roger Hooke

Earth Science Faculty Scholarship

Using the finite-element we have modeled the stress field near the calving face of an idealized tidewater glacier under a variety of assumptions about submarine calving-face height, subaerial calving-face height, and ice rheology These simulations all suggest that a speed maximum should be present at the calving face near the waterline. In experiments without crevassing, the decrease in horizontal velocity above this maximum culminates in a zone of longitudinal compression at the surface somewhat Up-glacier from the face. This zone of compression appears to be a consequence of the non-linear rheology of ice. It disappears when a linear rheology is …

Thickness Changes On Whillans Ice Stream And Ice Stream C, West Antarctica, Derived From Laser Altimeter Measurements, Vandy Blue Spikes, Beáta M. Csathó, Gordon S. Hamilton, Ian M. Whillans

Earth Science Faculty Scholarship

Repeat airborne laser altimeter measurements are used to derive surface elevation changes on parts of Whillans Ice Stream and Ice Stream C, West Antarctica. Elevation changes are converted to estimates of ice equivalent thickness change using local accumulation rates, surface snow densities and vertical bedrock motions. The surveyed portions of two major tributaries of Whillans Ice Stream are found to be thinning almost uniformly at an average rate of similar to 1 m a(-1). Ice Stream C has a complicated elevation-change pattern, but is generally thickening. These results are used to estimate the contribution of each surveyed region to the …

Relating Crevassing To Non-Linear Strain In The Floating Part Of Jakobshavn Isbrae, West Greenland, Paul R. Prescott, James P. Kenneally, Terence J. Hughes

Earth Science Faculty Scholarship

Jakobshavn Isbrae is a major ice stream that drains the west-central Greenland ice sheet and becomes afloat in Jakobshavn Isfiord (69degreesN, 49degreesW), where it has maintained the world's fastest-known sustained velocity and calving rate (7 km a(-1)) for at least four decades. The floating portion is approximately 12 km long and 6 km wide. Surface elevations and motion vectors were determined photogrammetrically for about 500 crevasses on the floating ice, and adjacent grounded ice, using aerial photographs obtained 2 weeks apart in July 1985. Surface strain rates were computed from a mesh of 399 quadrilateral elements having velocity measurements at …

Deductive Mathematics: An Introduction To Proof And Discovery For Mathematics Education, Andrew Wohlgemuth

Mathematics and Statistics Faculty Scholarship

Mathematics has two fundamental aspects: (1) discovery/logical deduction and (2) description/ computation. Discovery/deductive mathematics asks the questions:

1. What is true about this thing being studied?

2. How do we know it is true?

On the other hand, descriptive/computational mathematics asks questions of the type:

3. What is the particular number, function, and so on, that satisfies ... ?

4. How can we find the number, function, and so on?

In descriptive/computational mathematics, some pictorial, physical, or business situation is described mathematically, and then computational techniques are applied to the mathematical description, in order to find values of interest. The …

Maine's Salt Marshes: Their Functions, Values, And Restoration, Michele Dionne, Erno Bonebakker, Kristen Grant

Maine Sea Grant Publications

This illustrated resource booklet for Maine residents educates the reader about the properties and functions of salt marshes. It also facilitates leadership and participation in restoration efforts by providing information for further resources.

Field Guide To Phytoplankton In The Gulf Of Maine, Susan White

Maine Sea Grant Publications

This field 50-leaf guide was created for the citizen volunteers who provide a first-alert system to the Maine Department of Marine Resources by watching for the presence of potentially toxic phytoplankton along the coast. The waterproof cards (held in a three-ring binder) provide color images from light microscopes at 200X or 400X, as well as identifying characteristics, natural history facts, and known impacts of 22 types of phytoplankton. A glossary, size chart, bibliography, and a brief about zooplankton are also included.