Modern foraminiferal assemblages in northern Nares Strait, Petermann Fjord, and beneath Petermann ice tongue, NW Greenland

Calving events of Petermann Glacier, northwest Greenland, in 2010 and 2012 reduced the length of its ice tongue by c. 25 km, allowing exploration of newly uncovered seafloor during the Petermann 2015 Expedition. This article presents the results of foraminiferal analysis and environmental data from thirteen surface sediment samples in northern Nares Strait and Petermann Fjord, including beneath the modern ice tongue. This is the first study of living foraminifera beneath an arctic ice tongue and the first modern foraminiferal data from this area. Modern assemblages were studied to constrain species environmental preferences and to improve paleoenvironmental interpretations of foraminiferal assemblages. Sub–ice tongue assemblages differed greatly from those at all other sites, with very low faunal abundances and being dominated by agglutinated fauna, likely reflecting low food supply under the ice tongue. Fjord fauna were comprised of 80 percent or more calcareous species. Notably, Elphidium clavatum is absent beneath the ice tongue although it is dominant in the fjord. Increasing primary productivity associated with the transition to mobile sea ice, diminishing influence of the Petermann Glacier meltwater with distance from the grounding line, and increased influence of south-flowing currents in Nares Strait are the important controls on the faunal assemblages

Constraints on Lorentz violation from clock-comparison experiments

Constraints from clock-comparison experiments on violations of Lorentz and CPT symmetry are investigated in the context of a general Lorentz-violating extension of the standard model. The experimental signals are shown to depend on the atomic and ionic species used as clocks. Certain experiments usually regarded as establishing comparable bounds are in this context sensitive to different types of Lorentz violation. Some considerations relevant to possible future measurements are presented. All these experiments are potentially sensitive to Lorentz-violating physics at the Planck scale.Comment: accepted for publication in Physical Review D; scheduled for issue of December 1, 199

Plasma Dynamics

Contains table of contents for Section 2 and reports on three research projects.U.S. Navy - Office of Naval Research Grant N00014-90-J-4130Princeton University/Tokamak Physics Experiment Grant S-03688-GU.S. Department of Energy Grant DE-FG02-91-ER-54109National Science Foundation Grant ATM 94-2428

Utilizing reflex impairment to assess the role of discard mortality in ‘Size, Sex, and Season’ management for Oregon Dungeness crab (Cancer magister) fisheries

We found that crab discarded from Oregon (U.S.A.) commercial and recreational fisheries for Dungeness crab (Cancer magister) have lower post-release mortality than previously estimated. This aligns with the goals of the ‘3-S’ management strategy currently employed for these fisheries, to protect discarded sub-legal male (Size), female (Sex), and soft-shell (Season) crab. We found that, for the commercial ocean Dungeness fishery, overall discard mortality rates (five days after release) were 0.080 (95% Confidence Interval 0.061-0.100) for females; 0.012 (95% Confidence Interval 0.002-0.022) for hard-shell males; and 0.092 (95% Confidence Interval 0.026-0.157) for soft-shell males. The overall discard mortality rate for the recreational bay fishery (from a boat) was estimated to be 0.009 (95% Confidence Interval 0-0.018). A Reflex Action Mortality Predictor (RAMP) relationship, which relates reflex impairment to mortality probability, was created and utilized to estimate mortality rates. Our study highlights the importance of looking not only at discard and mortality rates to evaluate ‘3-S’ fishery management, but also the mortality- and bycatch-per-retained ratios, and temporal trends relative to changes in effort, animal condition, and catch composition.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Modern and early Holocene ice shelf sediment facies from Petermann Fjord and northern Nares Strait, northwest Greenland

Based on sediment cores and geophysical data collected from Petermann Fjord and northern Nares Strait, NW Greenland, an Arctic ice shelf sediment facies is presented that distinguishes sub and pro ice shelf environments. Sediment cores were collected from sites beneath the present day Petermann Ice Tongue (PIT) and in deglacial sediments of northern Nares Strait with a focus on understanding the glacial and oceanographic history over the last 11,000 cal yr BP. The modern sub ice shelf sediment facies in Petermann Fjord is laminated and devoid of coarse clasts (IRD) due to strong basal melting that releases debris (debris filtering) from the basal ice at the grounding zone driven by buoyant subglacial meltwater and entrained Atlantic Water. Laminated sediments in the deep basin proximal to the gounding zone comprise layers of fine mud formed by suspension settling from turbid meltwater plumes (plumites) interrupted by normally graded very fine sand to medium silt layers with sharp basal contacts and rip-up clasts of mud, interpreted as turbidites. An inner fjord sill limits distribution of sediment gravity flows from the grounding zone to the deep inner fjord basin, such that sites on the inner sill and beyond the ice tongue largely only comprise plumites. Bioturbation and foraminiferal abundances increase with distance from the grounding zone. The benthic foraminiferal species, Elphidium clavatum is absent beneath the ice tongue, but dominant in the turbid meltwater influenced environment beyond the ice tongue. The very sparse IRD in sediments beneath the PIT and in the fjord beyond the PIT derives mainly from englacial debris in the ice tongue, side valley glaciers, rock falls from the steep fjord walls and sea ice

'A Divided Soul'? the Cold War odyssey of O. John Rogge

In 1948 O. John Rogge, a prominent American liberal, was a contender for the Progressive Party's vice-presidential nomination. He was then a man of the Left: an activist in the international peace movement, a champion of radical causes and a defender of organizations deemed subversive by the Department of Justice. In 1951 he persuaded his\ud client to turn government witness in the Rosenberg espionage trial and was converted into 'Rogge the Rat' by his former allies. In tracing this transformation, this paper will argue that Rogge was neither a typical Cold War apostate nor a typical anti-Stalinist intellectual. Instead, his political trajectory was the outcome of a failed attempt to steer global politics away from Cold War dichotomies. The paper will therefore throw new light\ud both on the movement to find a 'third way' between East and West, and on the phenomenon of non-communist Left activism during the early Cold War