Some Effects of Oil on the Physical and Chemical Characteristics of Wet Tundra Soils

Crude hydrocarbons were added to the surface of wet tundra soils at Barrow, Alaska at volumes of 5 and 12 l/square metre. Physical and chemical effects in the soil were followed for three years. Soils treated with 5 l/square metre had their chemical and physical properties little altered. Those treated with 12 l/square metre recorded an increase in seasonal thaw, an increase in organic carbon and an increase in available phosphorus. Soil pH shifted toward neutrality. Decreases occurred in water infiltration rate and in plant available cations (Ca, Mg, K). Soil moisture, bulk density, shrinkage percent and total sulphur content appeared unaffected

Evolution of the Soil Landscape in the Sand Region of the Arctic Coastal Plain as Exemplified at Atkasook, Alaska

The Meade River region around the village of Atkasook, Alaska typifies much of the Arctic Coastal Plain underlain by aeolian sands. The forms and patterns of the landscape are formed mainly by ancient and active sand dunes and by channel shifts of the Meade River. Nearly all landforms, including those designated as primary, have had a polycyclic history throughout the last 10,000 years. The oldest and/or most stable landforms are low, broad dune ridges, interfluves, and lake divides. These have well-drained, reddish sandy soils with a distinct eluvial horizon and represent very extensive periods of development. Less well-drained sloping surfaces surrounding dune ridges and other primary landforms are covered by tussock tundra and all soils show the effect of cryoturbation. They range in age from 5,000 to 6,000 years. The development and stabilization of the primary landforms and the evolution of their soils are illustrated by similar much younger landforms. Generally, lowland areas associated with drained lake basins and cutoff meanders have a polygonal surface pattern and organic soils that range in age from a few thousand to at least 9,500 years. The majority of the polygonized terrain ranges in age from 4,000 to 5,000 years. Younger surfaces associated with the present course of the Meade River consist of alluvial terraces and active or partially stabilized sand dunes. The soils show little profile development. Their maximum age is on the order of 1,000 years

Observations on the Glacial History of Livingston Island

Livingston Island, one of the South Shetland Islands, Antarctica, has recorded at least three glacial events. During the oldest event, all areas of the island below 200 m were covered by an expanded island ice cap. At that time Livingston Island ice probably joined that of adjacent islands. A second, less extensive event, is recorded by deposits of both the inland ice cap and cirque glaciers. Between these two glacial events, a higher stand of sea level produced beaches and terraces at 10.6 m to 12 m above the present sea level. Following the second glacial event, a higher sea level produced beaches 6.1 m above the present sea level. A third, minor and probably relatively recent glacial event is recorded by push moraines in some cirques from which the ice has now receded.Observations sur l’histoire glaciaire de l’île de Livingston.  L’une des Shetland du Sud, en Antarctique, l’île de Livingston a vu au moins trois événements glaciaires.  Au cours du plus ancien, toute l’île en bas de la cote 200 m a été recouverte par une calotte insulaire.  A ce moment-là, la glace de Livingston rejoignait probablement celle des îles adjacentes.  Un second événement moins étendu est enregistré à la fois dans les dépôts de la calotte et dans ceux de glaciers de cirque.  Entre ces deux événements, un niveau marin plus élevé a produit des plages et des terrasses entre 10,6 et 12 m au-dessus du niveau marin actuel.  Après le second événement, une nouvelle remontée du niveau marin a produit des plages à 6,1 m au-dessus du niveau actuel.  Un troisième événement glaciaire, mineur et relativement récent, est enregistré dans les moraines de poussée de certains cirques dont la glace est maintenant disparue

Soil Development in the Mould Bay and Isachsen Areas, Queen Elizabeth Islands, Northwest Territories, Canada

On the cover: "RF 2503."Soils developed on the fine-grained sedimentary rocks of the Western Queen Elizabeth Islands illustrate well the weakening of the soil-forming processes with increasing latitude. Most of the soils of the Mould Bay area, Prince Patrick Island, are thin with weak morphological and chemical profiles. In contrast to the Tundra soils of northern Alaska and Victoria Island, the desertic soils of Prince Patrick Island are low in organic matter. They have developed largely under the processes of salinization and calcification. Their complex, mosaic associations reflect the dominant influence of subtle drainage changes. The soils of the Isachsen area of Ellef Ringnes Island are similar to those of Prince Patrick Island. However, profile development is even less well defined. The degree of expression of the soil-forming processes here has been reduced to almost nothing. The soils and soil-forming factors are expressed better on Prince Patrick Island, partly because of its more southerly latitude and somewhat more coarse-grained parent materials, and partly because the soil-forming factors there have had a greater uninterrupted period over which to operate.U.S. Army Natick Laboratorie

Effects of Crude and Diesel Oil Spills on Plant Communities at Prudhoe Bay, Alaska, and the Derivation of Oil Spill Sensitivity Maps

Crude oil was spilled on six of the major Prudhoe Bay plant communities at an intensity of 12 l/m². The communities occurred along a topographic-moisture gradient. The reaction of the major species of the various communities was recorded one year following the spills. Sedges and willows showed substantial recovery from crude oil spills. Mosses, lichens, and most dicotyledons showed little or no recovery. On a very wet plot with standing water, the vegetation showed total recovery one year following the spill. Dry plots, on the other hand, showed very poor recovery. Dryas integrifolia M. Vahl, the most important vascular species on dry sites, was killed. Identical experiments using diesel oil rather than crude oil showed all species except an aquatic moss to be killed. A sensitivity index for the communities was calculated on the basis of the percentage cover of the resistant species divided by the original total plant cover of the community. With this information an oil spill sensitivity map for an area of Prudhoe Bay was constructed using a vegetation map as a base. Using the crude oil data from Prudhoe Bay together with some from the literature, a predictive sensitivity map was also constructed for an accidental crude oil spill at nearby Franklin Bluffs. In this example all the community types are considered to have moderate to excellent recovery potential. Implications of the experiments and the mapping exercises for oil spill contingency planning are discussed

Gauge Unification in Supersymmetric Intersecting Brane Worlds

We show that contrary to first expectations realistic three generation supersymmetric intersecting brane world models give rise to phenomenologically interesting predictions about gauge coupling unification. Assuming the most economical way of realizing the matter content of the MSSM via intersecting branes we obtain a model independent relation among the three gauge coupling constants at the string scale. In order to correctly reproduce the experimentally known values of sin^2[theta_W(M_z)] and alpha_s(M_z) this relation leads to natural gauge coupling unification at a string scale close to the standard GUT scale 2 x 10^16 GeV. Additional vector-like matter can push the unification scale up to the Planck scale.Comment: 18 pages, harvmac & 3 figures; v2: one ref. adde

The Z-Z' Mass Hierarchy in a Supersymmetric Model with a Secluded U(1)'-Breaking Sector

We consider the Z'/Z mass hierarchy in a supersymmetric model in which the U(1)' is broken in a secluded sector coupled to the ordinary sector only by gauge and possibly soft terms. A large mass hierarchy can be achieved while maintaining the normal sparticle spectra if there is a direction in which the tree level potential becomes flat when a particular Yukawa coupling vanishes. We describe the conditions needed for the desired breaking pattern, to avoid unwanted global symmetries, and for an acceptable effective mu parameter. The electroweak breaking is dominated by A terms rather than scalar masses, leading to tan beta ~ 1. The spectrum of the symmetry breaking sector is displayed. There is significant mixing between the MSSM particles and new standard model singlets, for both the Higgs scalars and the neutralinos. A larger Yukawa coupling for the effective mu parameter is allowed than in the NMSSM because of the U(1)' contribution to the running from a high scale. The upper bound on the tree-level mass of the lightest CP even Higgs doublet mass is about c x 174 GeV, where c is of order unity, but the actual mass eigenvalues are generally smaller because of singlet mixing.Comment: Latex, 12 Tables, 22 page

Baryon number violation, baryogenesis and defects with extra dimensions

In generic models for grand unified theories(GUT), various types of baryon number violating processes are expected when quarks and leptons propagate in the background of GUT strings. On the other hand, in models with large extra dimensions, the baryon number violation in the background of a string is not trivial because it must depend on the mechanism of the proton stabilization. In this paper we argue that cosmic strings in models with extra dimensions can enhance the baryon number violation to a phenomenologically interesting level, if the proton decay is suppressed by the mechanism of localized wavefunctions. We also make some comments on baryogenesis mediated by cosmological defects. We show at least two scenarios will be successful in this direction. One is the scenario of leptogenesis where the required lepton number conversion is mediated by cosmic strings, and the other is the baryogenesis from the decaying cosmological domain wall. Both scenarios are new and have not been discussed in the past.Comment: 20pages, latex2e, comments and references added, to appear in PR

Physics Implications of Flat Directions in Free Fermionic Superstring Models II: Renormalization Group Analysis

We continue the investigation of the physics implications of a class of flat directions for a prototype quasi-realistic free fermionic string model (CHL5), building upon the results of the previous paper in which the complete mass spectrum and effective trilinear couplings of the observable sector were calculated to all orders in the superpotential. We introduce soft supersymmetry breaking mass parameters into the model, and investigate the gauge symmetry breaking patterns and the renormalization group analysis for two representative flat directions, which leave an additional $U(1)'$ as well as the SM gauge group unbroken at the string scale. We study symmetry breaking patterns that lead to a phenomenologically acceptable $Z-Z'$ hierarchy, $M_{Z^{'}} \sim {\cal O}(1~{\rm TeV})$ and $10^{12}~{\rm GeV}$ for electroweak and intermediate scale $U(1)^{'}$ symmetry breaking, respectively, and the associated mass spectra after electroweak symmetry breaking. The fermion mass spectrum exhibits unrealistic features, including massless exotic fermions, but has an interesting $d$-quark hierarchy and associated CKM matrix in one case. There are (some) non-canonical effective $\mu$ terms, which lead to a non-minimal Higgs sector with more than two Higgs doublets involved in the symmetry breaking, and a rich structure of Higgs particles, charginos, and neutralinos, some of which, however, are massless or ultralight. In the electroweak scale cases the scale of supersymmetry breaking is set by the $Z^{'}$ mass, with the sparticle masses in the several TeV range.Comment: 38 pages, 5 figures, LaTex. Minor correction

CP Violation in Supersymmetric U(1)' Models

The supersymmetric CP problem is studied within superstring-motivated extensions of the MSSM with an additional U(1)' gauge symmetry broken at the TeV scale. This class of models offers an attractive solution to the mu problem of the MSSM, in which U(1)' gauge invariance forbids the bare mu term, but an effective mu parameter is generated by the vacuum expectation value of a Standard Model singlet S which has superpotential coupling of the form SH_uH_d to the electroweak Higgs doublets. The effective mu parameter is thus dynamically determined as a function of the soft supersymmetry breaking parameters, and can be complex if the soft parameters have nontrivial CP-violating phases. We examine the phenomenological constraints on the reparameterization invariant phase combinations within this framework, and find that the supersymmetric CP problem can be greatly alleviated in models in which the phase of the SU(2) gaugino mass parameter is aligned with the soft trilinear scalar mass parameter associated with the SH_uH_d coupling. We also study how the phases filter into the Higgs sector, and find that while the Higgs sector conserves CP at the renormalizable level to all orders of perturbation theory, CP violation can enter at the nonrenormalizable level at one-loop order. In the majority of the parameter space, the lightest Higgs boson remains essentially CP even but the heavier Higgs bosons can exhibit large CP-violating mixings, similar to the CP-violating MSSM with large mu parameter.Comment: 29 pp, 3 figs, 2 table