Copenhagen,Climate Science and the Emotional Geographies of Climate Change

The Pacific island nation-state of Tuvalu featured significantly at the Copenhagen Conference of Parties (COP) 15 climate change negotiations, where the vulnerability of Tuvalu to sea level rise and emotional outpourings of the Tuvaluan delegation contributed to the nation's prominence. In this paper we discuss the likely impacts for Tuvalu of a 1.5°C versus 2°C global warming target and explore sadness and discomfort surrounding discussion of these targets during COP 15. We highlight tensions between science and emotion, arguing that affective encounters can be significant in climate change decision-making. Weeping by a member of the Tuvalu delegation evoked discomfort in the conference plenary. This discomfort briefly unsettled the apparently stable boundaries of convention and protocol that seek to separate emotion from science and politics. We argue that possibilities for change arise when emotions enter climate change negotiations, even though (or perhaps because) these are arenas that privilege rational exchange. Our conclusion urges that more attention be paid to how climate science and emotion are intertwined in climate change politics.     

Deformation-related microstructures in magmatic zircon and implications for diffusion

An undeformed glomeroporphyritic andesite from the Sunda Arc of Java, Indonesia, contains zoned plagioclase and amphibole glomerocrysts in a fine-grained groundmass and records a complex history of adcumulate formation and subsequent magmatic disaggregation. A suite of xenocrystic zircon records Proterozoic and Archaean dates whilst a discrete population of zoned, euhedral, igneous zircon yields a SHRIMP U-Pb crystallisation age of 9.3 ± 0.2 Ma. Quantitative microstructural analysis of zircon by electron backscatter diffraction (EBSD) shows no deformation in the inherited xenocrysts, but intragrain orientation variations of up to 30° in 80% of the young zircon population. These variations are typically accommodated by both progressive crystallographic bending and discrete low angle boundaries that overprint compositional growth zoning. Dispersion of crystallographic orientations are dominantly by rotation about an axis parallel to the zircon c-axis [001], which is coincident with the dominant orientation of misorientation axes of adjacent analysis points in EBSD maps. Less common <100> misorientation axes account for minor components of crystallographic dispersion. These observations are consistent with zircon deformation by dislocation creep and the formation of tilt and twist boundaries associated with the operation of <001>{100} and <100>{010} slip systems. The restriction of deformation microstructures to large glomerocrysts and the young magmatic zircon population, and the absence of deformation within the host igneous rock and inherited zircon grains, indicate that zircon deformation took place within a low-melt fraction (<5% melt), mid-lower crustal cumulate prior to fragmentation during magmatic disaggregation and entrainment of xenocrystic zircons during magmatic decompression. Tectonic stresses within the compressional Sunda Arc at the time of magmatism are considered to be the probable driver for low-strain deformation of the cumulate in the late stages of initial crystallisation. These results provide the first evidence of crystal plastic dislocation creep in zircon associated with magmatic crystallisation and indicate that the development of crystal-plastic microstructures in zircon is not restricted to high-strain rocks. Such microstructures have previously been shown to enhance bulk diffusion of trace elements (U, Th and REE) in zircon. The development of deformation microstructures, and therefore multiple diffusion pathways in zircon in the magmatic environment, has significant implications for the interpretation of geochemical data from igneous zircon and the trace element budgets of melts due to the potential enhancement of bulk diffusion and dissolution rates.     

Optical spectroscopy of GX 339−4 during the high–soft and low–hard states – I

We carried out spectroscopic observations of the candidate black hole binary GX 339−4 during its low–hard and high–soft X-ray states. We have found that the spectrum is dominated by emission lines of neutral elements with asymmetric, round-topped profiles in the low–hard state. In the high–soft state, however, the emission lines from both neutral and ionized elements have unambiguously resolved double-peaked profiles. The detection of double-peaked emission lines in the high–soft state, with a larger peak separation for higher ionization lines, indicates the presence of an irradiatively heated accretion disc. The round-topped lines in the low–hard state are probably caused by a dense matter outflow from an inflated non-Keplerian accretion disc. Our data do not show velocity modulations of the line centres caused by the orbital motion of the compact object, neither do the line basewidths show substantial variations in each observational epoch. There are no detectable absorption lines from the companion star. All these features are consistent with those of a system with a low-mass companion star and low orbital inclination.     

Effects of local drought condition on public opinions about water supply and future climate change

A growing body of research indicates that opinions about long-term climate change and other natural resource issues can be significantly affected by current weather conditions (e.g., outside air temperature) and other highly contingent environmental cues. Although increased severity and frequency of droughts is regarded as a likely consequence of anthropogenic climate change, little previous research has attempted to relate the experience of drought with public attitudes about water supply or water-related climate change issues. For this study, a large set (n?=?3,163) of public survey data collected across nine states of the southern United States was spatio-temporally linked with records of short-term (~12 weeks) and long-term (~5 years) drought condition at the level of each respondent’s zip code. Multivariate ordinal logistic regression models that included numerous other independent variables (environmental ideology, age, gender, education, community size, residency duration, and local annual precipitation) indicated highly significant interactions with long-term drought condition, but showed no significant effect from short-term drought condition. Conversely, attitudes about water-related climate change showed highly significant interactions with short-term drought, with weaker to no effects from long-term drought. While the finding of significant effects from short-term drought condition on opinions about future drought is broadly consistent with previous public opinion research on climate change, the finding of water supply attitudes being more responsive to longer term drought condition is, to our knowledge, a novel result. This study more generally demonstrates the methodological feasibility and applied importance of accounting for local drought condition when public opinion information is used to evaluate outreach programs for water conservation and climate change.     

A Triple‐Stack Column Procedure for Rapid Separation of Cu and Zn from Geological Samples

We present a new procedure for the separation and purification of Cu and Zn from geological samples. Our procedure employed a single pass, triple‐stack column set‐up. The first column, filled with TRU resin (TrisKem International), quantitatively removed Fe and Ti from sample matrices. A second column, filled with pre‐filter resin (TrisKem International), removed organic compounds. Finally, a third column, filled with anion exchange resin (AG1‐X8, 200–400 mesh, Bio‐Rad), was used to separate Cu and Zn from the remaining matrix. Our procedure required about 50% less acid volume than previously reported methods for Cu and Zn separation, thereby minimising analytical blanks and column running times. Copper and Zn stable isotope ratios were determined by a Thermo Neptune Plus MC‐ICP‐MS using Zn and Cu external normalisation, respectively, in addition to sample‐standard bracketing to correct for instrumental mass bias. We explore the inter‐calibration of Cu and Zn isotope fractionation coefficients during analysis by measuring mixed Cu–Zn solutions with enhanced mass bias variation generated by varying sample gas flow rates. Our results demonstrate that this procedure is useful when variation in instrumental mass bias throughout analytical sequences is insufficient to inter‐calibrate Cu and Zn fractionation coefficients.     

Thermoluminescence dating and geochemistry of loessic deposits in southeast England

The results of a thermoluminescence (TL) dating and geochemical survey of loessic deposits in southeast England, involving sampling at 26 localities, demonstrate that the loessic deposits appear to be the product of at least three depositional phases of aeolian silt during the Late Pleistocene, namely 10-25 ka BP, 50–125 ka BP and > 170 ka BP. The majority of localities sampled date to the Late Devensian, but isolated pockets of older material were found throughout the area. The majority of the samples analysed were of decalcified material. The results of geochemical analyses of major oxide and trace element concentrations indicate the uniformity of material and suggest a common provenance.     

Thermal desorption of water ice in the interstellar medium

Water (H₂O) ice is an important solid constituent of many astrophysical environments. To comprehend the role of such ices in the chemistry and evolution of dense molecular clouds and comets, it is necessary to understand the freeze-out, potential surface reactivity and desorption mechanisms of such molecular systems. Consequently, there is a real need from within the astronomical modelling community for accurate empirical molecular data pertaining to these processes. Here we give the first results of a laboratory programme to provide such data. Measurements of the thermal desorption of H₂O ice, under interstellar conditions, are presented. For ice deposited under conditions that realistically mimic those in a dense molecular cloud, the thermal desorption of thin films (≪50 molecular layers) is found to occur with zeroth-order kinetics characterized by a surface binding energy, E _des, of 5773 ± 60 K, and a pre-exponential factor, A , of 10^30 ± 2 molecules cm⁻² s⁻¹. These results imply that, in the dense interstellar medium, thermal desorption of H₂O ice will occur at significantly higher temperatures than has previously been assumed.     

The 1986 Kermadec earthquake and its relation to plate segmentation

To evaluate the tectonic significance of the October 20, 1986 Kermadec earthquake (M _w =7.7), we performed a comprehensive analysis of source parameters using surface waves, body waves, and relocated aftershocks. Amplitude and phase spectra from up to 93 Rayleigh waves were inverted for centroid time, depth, and moment tensor in a two-step algorithm. In some of the inversions, the time function was parameterized to include information from the body-wave time function. The resulting source parameters were stable with respect to variations in the velocity and attenuation models assumed, the parameterization of the time function, and the set of Rayleigh waves included. The surface wave focal mechanism derived (=275°, =61°, =156°) is an oblique-compressional mechanism that is not easy to interpret in terms of subduction tectonics. A seismic moment of 4.5×10²⁰ N-m, a centroid depth of 45±5 km, and a centroid time of 13±3 s were obtained. Directivity was not resolvable from the surface waves. The short source duration is in significant contrast to many large earthquakes.We performed a simultaneous inversion ofP andSH body waves for focal mechanism and time function. The focal mechanism agreed roughly with the surface wave mechanism. Multiple focal mechanisms remain a possibility, but could not be resolved. The body waves indicate a short duration of slip (15 to 20 s), with secondary moment release 60s later. Seismically radiated energy was computed from the body-wave source spectrum. The stress drop computed from the seismic energy is about 30 bars. Sixty aftershocks that occurred within three months of the mainshock were relocated using the method of Joint Hypocentral Determination (JHD). Most of the aftershocks have underthrusting focal mechanisms and appear to represent triggered slip on the main thrust interface. The depth, relatively high stress drop, short duration of slip, and paucity of true aftershocks are consistent with intraplate faulting within the downgoing plate. Although it is not clear on which nodal plane slip occurred, several factors favor the roughly E-W trending plane. The event occurred near a major segmentation in the downgoing plate at depth, near a bend in the trench, and near a right-lateral offset of the volcanic are by 80 km along an E-W direction. Also, all events in the region from 1977 to 1991 with CMT focal mechanisms similar to that of the Mainshock occurred near the mainshock epicenter, rather than forming an elongate zone parallel to the trench as did the aftershock activity. We interpret this event as part of the process of segmentation or tearing of the subducting slab. This segmentation appears to be related to the subduction of the Louisville Ridge, which may act as an obstacle to subduction through its buoyancy.