Panphasia: a user guide

We make a very large realisation of a Gaussian white noise field, called PANPHASIA, public by releasing software that computes this field. Panphasia is designed specifically for setting up Gaussian initial conditions for cosmological simulations and resimulations of structure formation. We make available both software to compute the field itself and codes to illustrate applications including a modified version of a public serial initial conditions generator. We document the software and present the results of a few basic tests of the field. The properties and method of construction of Panphasia are described in full in a companion paper Jenkins 2013.Comment: 11 pages, 2 figures. Software to calculate Panphasia is available from: http://icc.dur.ac.uk/Panphasia.ph

Centurial‐millenial ice‐rafted debris pulses from ablating marine ice sheets

We use an ice‐sheet model to show that (i) margins of marine ice‐sheets can be expected to be frozen to the bed, except where ice‐streams discharge; (ii) 20–50km retreats induced by ablation rates of 2 m/yr provide sufficient debris flux through the grounding line to produce large sedimentation events. Such ablation would reduce ice‐shelf extent markedly, permitting debris to reach the calving front and be transported by icebergs leading to ice‐rafted debris (IRD) events. Ice shelf break‐up takes around a century (start of IRD pulse), while the creation of warm‐based conditions (end of IRD pulse) due to upwards motion of warm ice takes a few more centuries. Such IRD pulses are unlikely to explain Heinrich events, which are associated with relatively cold periods within glaciations. Surges are not necessary conditions for the production of large IRD events

A simple model of the ice-shelf-ocean boundary layer and current

Ocean-forced basal melting has been implicated in the widespread thinning of Antarctic ice shelves, but our understanding of what determines melt rates is hampered by our limited knowledge of the buoyancy- and frictionally-controlled flows along the ice shelf base that regulate heat transfer from ocean to ice. In an attempt to address this deficiency, a simple model of a buoyant boundary flow, considering only the spatial dimension perpendicular to the boundary, is presented. Results indicate that two possible flow regimes exist: a weakly-stratified, geostrophic cross-slope current with upslope flow within a buoyant Ekman layer; or a strongly-stratified upslope current with a weak cross-slope flow. The latter regime, which is analogous to the steady solution for a katabatic wind, is most appropriate when the ice-ocean interface is steep. For the gentle slopes typical of Antarctic ice shelves the buoyant Ekman regime, which has similarities with the case of an unstratified density current on a slope, provides some useful insight. When combined with a background flow, a range of possible near-ice current profiles emerge as a result of arrest or enhancement of the upslope Ekman transport. A simple expression for the upslope transport can be formed that is analogous to that for the wind-forced surface Ekman layer, with curvature of the ice shelf base replacing the wind-stress curl in driving exchange between the Ekman layer and the geostropic current below

Reducing the Risk of Police Corruption in Guatemala

The country of Guatemala has always been plagued by political, security, and socio-economic conditions. These issues have contributed to the country having one of the highest violent crime rates in Central America and being ranked as the third most murderous country in the entire world (Grann, D.). This project will examine one of the factors believed to be most prominent in the country’s security problem, police corruption. The Guatemalan National Civil Police (PNC) officers are confronted with institutional corruption, a homicide rate over five times the world average, insufficient resources, poor training, and distrust from the civilian population (ghrc-usa, 2014). “The U.S. State Department 2077 Guatemala Country Report on Human Rights Practices states that “Members of the police force committed a number of unlawful killings. Corruption, intimidation, and ineffectiveness within the police department and other institutions prevented adequate investigation of many such killings, as well as the arrest and successful prosecution of perpetrators.” (ghrc-usa, 2014). Another challenge for the PNC is drug trafficking. Guatemalan President Alvaro Colom blames the drug traffickers for the corruption plaguing the PNC. Drug traffickers have been able to corrupt many PNC officers and chiefs because they have the ability to pay more than the monthly salaries these people receive. Mexican drug cartels such as the Los Zetas and the Mara Salvatrucha actively operate throughout the country. In addition, Guatemala’s geographical location makes it a key country for trafficking in cocaine and heroin from South America en route to the U.S. and Europehttps://scholarscompass.vcu.edu/uresposters/1046/thumbnail.jp

Geology of the Mercury Quadrangle, McCulloch County, Texas

A new map showing detailed geology of the Mercury quadrangle, and 18 detailed, newly measured and described stratigraphic sections within the quadrangle are the main part of this paper. Lower Ordovician, Mississippian, Pennsylvanian, Cretaceous, and quaternary strata are exposed. Pennsylvanian beds unconformably overlap older Paleozoic formations, and Cretaceous formations truncate Pennsylvanian strata. Sandstone and conglomerate channel deposits, occurring at many levels in the Pennsylvanian sequence, are interpreted as indicators of repeated uplift and erosion of nearby land areas. These irregular deposits complicate accurate correlation of marker beds. Limestone reefs are found in three zones in the upper Canyon series. Interpretation of these limestone masses as reefs permits clarification of several correlation problems. The development of reefs, one above another along northeast southwest trends, suggests shallow, warm, clear water conditions of deposition. The nomenclature of the Canyon series is simplified by elevating former member names to formational rank. The Corn Creek limestone member of the Placid formation is the only new name proposed. Lower Paleozoic beds are folded broadly into the Hall uplift in the southwestern part of the quadrangle. Strawn, Canyon, and Cisco beds, covering 60 percent of the quadrangle, dip northwestward 60 feet per mile, and Cretaceous strata in the southwestern part of the area dip southward 10 feet per mile.Geological Science

Index of Authors: 2005–2006

Index of Author

Index of Articles: 2005–2006

Index of Article

Front Matter

Front Matte