Suffocation of pilchards (Sardinops sagax) by a green microalgal bloom in Wellington Harbour,New Zealand

A bloom of the green microalga Tetraselmis sp. in a small lagoon in Wellington Harbour, New Zealand, is considered to have caused a fish kill of pilchards (Sardinops sagax). The fish deaths are attributed to anoxia brought about by a combination of reduced dissolved oxygen levels and the microalgae sticking to and clogging the secondary gill lamellae of the fish.     

Fishes from Porirua and Pauatahanui inlets: Occurrence in gill nets

From June 1983 to July 1984, gill nets were set at intervals of approximately one month in the Porirua and Pauatahanui Inlets, Wellington. During this period, 24 species of fish were caught, bringing the total number of species known from the two inlets to 43. The inlets are a nursery area for juvenile Callorhynchus milii, Mustelus lenti‐culatus, Rhombosolea plebeia, and Arripis trutta.     

Estimates of carbon stored in harvested wood products from the United States forest service northern region, 1906-2010

Background  

Global forests capture and store significant amounts of CO₂ through photosynthesis. When carbon is removed from forests through harvest, a portion of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux associated with harvested wood products (HWP) to meet greenhouse gas monitoring commitments and climate change adaptation and mitigation objectives. This paper uses the Intergovernmental Panel on Climate Change (IPCC) production accounting approach and the California Forest Project Protocol (CFPP) to estimate HWP carbon storage from 1906 to 2010 for the USFS Northern Region, which includes forests in northern Idaho, Montana, South Dakota, and eastern Washington.     

Assessment of pingo distribution and morphometry using an IfSAR derived digital surface model, western Arctic Coastal Plain, Northern Alaska

Pingos are circular to elongate ice-cored mounds that form by injection and freezing of pressurized water in near-surface permafrost. Here we use a digital surface model (DSM) derived from an airborne Interferometric Synthetic Aperture Radar (IfSAR) system to assess the distribution and morphometry of pingos within a 40,000 km² area on the western Arctic Coastal Plain of northern Alaska. We have identified 1247 pingo forms in the study region, ranging in height from 2 to 21 m, with a mean height of 4.6 m. Pingos in this region are of hydrostatic origin, with 98% located within 995 drained lake basins, most of which are underlain by thick eolian sand deposits. The highest pingo density (0.18 km^− 2) occurs where streams have reworked these deposits. Morphometric analyses indicate that most pingos are small to medium in size (< 200 m diameter), gently to moderately sloping (< 30°), circular to slightly elongate (mean circularity index of 0.88), and of relatively low height (2 to 5 m). However, 57 pingos stand higher than 10 m, 26 have a maximum slope greater than 30°, and 42 are larger than 200 m in diameter. Comparison with a legacy pingo dataset based on 1950s stereo-pair photography indicates that 66 may have partially or completely collapsed over the last half-century. However, we mapped over 400 pingos not identified in the legacy dataset, and identified only three higher than 2 m to have formed between ca. 1955 and ca. 2005, indicating that caution should be taken when comparing contemporary and legacy datasets derived by different techniques. This comprehensive database of pingo location and morphometry based on an IfSAR DSM may prove useful for land and resource managers as well as aid in the identification of pingo-like features on Mars.     

Dissociation kinetics of Fe(III)- and Al(III)-natural organic matter complexes at pH 6.0 and 8.0 and 25 °C

The rate at which iron- and aluminium-natural organic matter (NOM) complexes dissociate plays a critical role in the transport of these elements given the readiness with which they hydrolyse and precipitate. Despite this, there have only been a few reliable studies on the dissociation kinetics of these complexes suggesting half-times of some hours for the dissociation of Fe(III) and Al(III) from a strongly binding component of NOM. First-order dissociation rate constants are re-evaluated here at pH 6.0 and 8.0 and 25 °C using both cation exchange resin and competing ligand methods for Fe(III) and a cation exchange resin method only for Al(III) complexes. Both methods provide similar results at a particular pH with a two-ligand model accounting satisfactorily for the dissociation kinetics results obtained. For Fe(III), half-times on the order of 6-7 h were obtained for dissociation of the strong component and 4-5 min for dissociation of the weak component. For aluminium, the half-times were on the order of 1.5 h and 1-2 min for the strong and weak components, respectively. Overall, Fe(III) complexes with NOM are more stable than analogous complexes with Al(III), implying Fe(III) may be transported further from its source upon dilution and dispersion.     

Walter Benjamin’s Dionysian Adventures on Google Earth

This paper argues, following Friedrich Nietzsche, that recent evaluations of Google Earth uncritically privilege the product’s Apollonian determinations at the expense of its Dionysian uncertainties. Specifically, when we understand Google Earth as a virtual globe composed of surveyed panoramas, sober rationalization, dystopic control, and transparent order – or, even, as a tool for participation and empowerment – we undersell its capacities as an alluring digital peep-box, an uncertain orb spangled with vertiginous paranoia, frenzied navigation, jubilatory dissolution, and intoxicating giddiness. We argue that the former interpretations not only risk foreclosing our theorizations about how Google Earth is actually used in various ways and different contexts, they also reproduce a one-dimensional and conservative reading of technology that can be traced back (at least) to the writings of Theodor Adorno. By drawing on the work of Walter Benjamin (Adorno’s critic and pen pal for more than a decade) we aim to ‘go beyond Apollo and Adorno’ by illustrating the extent to which Apollonian order and Dionysian love makes Google Earth go round. To do this, we examine Google Earth as a “digital peep-box” with an online collective that revels in its “Spot the Black Helicopter” competitions; illuminated profanities; alien and giant insect invaders; naked sunbathers; and crashed transport planes in Darfur.     

Climate change, patch choice, and intensification at Pont d'Ambon (Dordogne, France) during the Younger Dryas

This paper considers the impact of the Younger Dryas on the prehistoric inhabitants of Pont d'Ambon, a site in the Dordogne region of southwestern France, through an examination of the zooarchaeological remains from this site. An investigation of patch choice indicates that patch choice evenness declines during the Younger Dryas due to increasing local dominance of the grassland patch. Analyses of demographic composition, cutmark frequency, and marrow processing in the wild European rabbit (Oryctolagus cuniculus) assemblage suggest intensified rabbit use during this period. This study thus supports the hypothesis that changing climate had significant impacts on the prehistoric inhabitants of Pont d'Ambon. However, the traditional climate hypothesis—that changing climate negatively impacted the availability of larger fauna, forcing a switch to smaller, lower-ranked prey items—is not supported here. The inhabitants of Pont d'Ambon seem to have adapted to changing climate by efficiently exploiting the new species available to them, and possibly, during the Younger Dryas, by intensifying their use of one of these new species, the European rabbit.     

Climate and vegetation history from a 14,000-year peatland record, Kenai Peninsula, Alaska

Analysis of pollen, spores, macrofossils, and lithology of an AMS ¹⁴C-dated core from a subarctic fen on the Kenai Peninsula, Alaska reveals changes in vegetation and climate beginning 14,200 cal yr BP. Betula expansion and contraction of herb tundra vegetation characterize the Younger Dryas on the Kenai, suggesting increased winter snowfall concurrent with cool, sunny summers. Remarkable Polypodiaceae (fern) abundance between 11,500 and 8500 cal yr BP implies a significant change in climate. Enhanced peat preservation and the occurrence of wet meadow species suggest high moisture from 11,500 to 10,700 cal yr BP, in contrast to drier conditions in southeastern Alaska; this pattern may indicate an intensification and repositioning of the Aleutian Low (AL). Drier conditions on the Kenai Peninsula from 10,700 to 8500 cal yr BP may signify a weaker AL, but elevated fern abundance may have been sustained by high seasonality with substantial snowfall and enhanced glacial melt. Decreased insolation-induced seasonality resulted in climatic cooling after 8500 cal yr BP, with increased humidity from 8000 to 5000 cal yr BP. A dry interval punctuated by volcanic activity occurred between 5000 and 3500 cal yr BP, followed by cool, moist climate, coincident with Neoglaciation. Tsuga mertensiana expanded after ~ 1500 cal yr BP in response to the shift to cooler conditions.     

Novel C15 sesquiterpanes in Niger Delta oils: Structural identification and potential application as new markers of angiosperm input in light oils

Two new C₁₅ sesquiterpanes have been isolated from a Niger Delta oil. Based on nuclear magnetic resonance (NMR) data, their structures are similar to the ring D and E part of oleanane. The mass spectra show an m/z 193 base peak typical of rearranged drimanes. They have been found only in oleanane-containing oils with a Cretaceous or Tertiary source. Data are presented for 34 such oils from Angola, Canada, Greece, India, Indonesia, Iran, New Zealand, Nigeria, Thailand and Vietnam. The ratio between the new sesquiterpanes and rearranged drimanes roughly follows the oleanane index. They are absent from marine oils whose source rock age (Jurassic or older) predates the evolution and proliferation of angiosperms. They are probably formed via degradation of functionalized oleanoids or by cleavage of seco-oleananes. These sesquiterpanes may be useful as markers of angiosperm input in light oils (jet fuel, diesel or condensates) usually devoid of higher molecular weight markers for higher plant input.     

Numerical modeling of the development of a preferentially leached layer on feldspar surfaces

Compositional depth profiles in the leached layer of feldspar surfaces are usually interpreted by using analytical solutions which introduce oversimplifying assumptions. Here we present a general multicomponent interdiffusion numerical model for simulating cation release from a preferentially leached layer on feldspar surfaces in acid solutions. The numerical model takes into account interdiffusion, dissolution of the solid phase (represented by a moving boundary problem), and adsorption in the leached layer. Effective diffusion coefficients of ions vary with concentration along the leached layer. Governing equations of ions diffusion in the leached layer are solved numerically with a finite element method implemented in a multicomponent reactive transport code, CORE^3D, previously verified against analytical solutions of compositional depth profiles. The numerical model is tested with published X-ray photoelectron spectroscopy (XPS) data on early development of compositional profiles of labradorite leached in pH 2 HCl solutions. Model parameters are estimated by fitting depth profiles of Ca and Al measured at 12, 26, 48, 72, and 143 h. The best fit is achieved with tracer diffusion coefficients of 4 × 10⁻¹⁸, 8 × 10⁻¹⁷, 3.4 × 10⁻¹⁷, and 7 × 10⁻¹⁸ cm²/s for H, Na, Ca, and Al, respectively, which fall within the range of values reported in the literature. Our estimate of the retreat velocity corresponding to the dissolution rate is 3 × 10⁻¹³ cm/s. Results of sensitivity runs show that computed compositional profiles are sensitive to most model parameters.