Satellite imagery and the spectacle of secret spaces

This paper documents and assesses emerging efforts to resist and subvert deep-seated and long-held governmental secrecy over geographical spaces of military/security activities and other sites deemed sensitive by the state. It explores tensions in new web-served mapping and high-resolution imagery of these sites, which view them though ‘pin holes’ of publicly available data. These ‘counter-mappings’ focus attention on the significance of sites that are either buried unnoticed in seamless global image coverage, or else censored on official mapping. Some reveal a tenaciously anti-hegemonic and oppositional discourse, others a more playful set of cultural practices, one that ridicules as much as directly resists. We situate these newly witnessed secret sites in contemporary visual culture, exploring the spectacular and Debordian possibilities of resistance that they offer, and evaluate the significance and ironies of these diverse imaging practices.     

Ecologies of actor-networks and (non)social labor within the urban political economies of nature

On September 16th, 2005 the United States began restricting the entry of commodities shipped from abroad in wood packaging materials that do not conform to phytosanitation measures meant to prevent the spread of pests and pathogens. This action results from expensive lessons learned as global commerce facilitates pandemics like Dutch elm disease. Marxist political ecology is well suited to investigate such scenarios with its emphasis on the social production of nature within accumulation regimes. Some scholars contend, however, that Marxist accounts of the contradictions that result from nature’s commodification relegate nonhuman organisms to an apolitical role in environmental transformation while reinforcing the nature/society dichotomy. Often viewed as antithetical to Marxism, actor-network theory or ANT emphasizes the ability of actants (both human and nonhuman) to enroll other actants into heterogeneous assemblages or networks. Thus, it is claimed that nonhuman organisms can be attributed ontological status in processes of environmental change, much like their human counterparts. Despite this apparent theoretical discord, political ecologists are increasingly integrating aspects of both Marx and ANT into their analyses. But a more explicit articulation of the ontological basis and epistemic import of theoretical synthesis is warranted. This paper therefore prioritizes and links the ontological status of labor in both of these theories in order to expand the definition of urban environmental politics to include the role of nonhuman organisms. By demonstrating the laboring capacity of Dutch elm disease within the networks of urban political economy, the epistemology of environmental politics is thus expanded.     

Thermochemistry of (Fe2+, Mg)SiO3 orthopyroxene

Enthalpies of solution in eutectic (Li, Na)₂B₂O₄ melts at 1023 K were measured for five synthetic orthopyroxenes on the join MgSiO₃-FeSiO₃. The pyroxenes were synthesized at 1120°C and 20 kbar and thus were presumed to be highly disordered. The measurements indicate a small positive enthalpy of mixing, with W_H = 950 cal/MSiO₃.Enthalpy of solution measurements were made on a natural, well-ordered orthopyroxene near the composition En_52.5Fs_47.5 and on this material after heat-treatment at 1150°C and 20 kbar. Irreversible expansion of the unit-cell constants of the natural pyroxene after heat-treatment at various temperatures was used to characterize the degree of M-site disorder. The observed enthalpy of solution decrement of 0.85 kcal/MSiO₃ between the natural En_52.5 and the same material heated at 1150° corresponds to about half of the maximum possible disordering, or ΔX_Fe^M1? 0.25, which leads to a ΔH of 7.5 kcal/M₂Si₂O₆, for the exchange reaction: Fe(M2) + Mg(Ml) = Fe(Ml) + Mg(M2) if M-site interaction energy terms are ignored. This ΔH is larger than inferred from any of the analyses of site-occupancy data except that of Besancon (1981), who gave a very similar value. The measured ΔH of disorder and the W_H of mixing together indicate a large ΔH as great as 3.2 kcal for the reciprocal reaction: Fe₂Si₂O₆ + Mg₂Si₂O₆ = Fe(M2)Mg(M1)Si₂O₆ + Fe(M1)Mg(M2)Si₂O₆ as anticipated by Sack (1980).As a consequence of the inferred magnitudes of ΔHof the exchange and reciprocal reactions, departures from ideality of Gibbs energy of mixing of orthopyroxene are very small at 700°–1000°C. Activities of MgSiO₃ and FeSiO₃ may be replaced by their mol fractions at all temperatures in most petrologic calculations.     

A seismic hazard map of India and adjacent areas

We have produced a probabilistic seismic hazard map showing peak ground accelerations in rock for India and neighboring areas having a 10% probability of being exceeded in 50 years. Seismogenic zones were identified on the basis of historical seismicity, seismotectonics and geology of the region. Procedures for reducing the incompleteness of earthquake catalogs were followed before estimating recurrence parameters. An eastern United States acceleration attenuation relationship was employed after it was found that intensity attenuation for the Indian region and the eastern United States was similar. The largest probabilistic accelerations are obtained in the seismotectonic belts of Kirthar, Hindukush, Himalaya, Arakan-Yoma, and the Shillong massif where values of over 70% g have been calculated.     

On the observation of 92Nb and 94Nb in nature

Radioactivity measurements have shown evidence for long-lived ⁹²Nb and $\text{2.03 × 10}{}^4\text{yr}{}^{94}\text{Nb}$ in natural niobium. The specific activity of ⁹⁴Nb was observed to be 0.32 ± 0.03 dis/min. kg Nb and that of ⁹²Nb to be 0.058 ± 0.035 dis/min. kg Nb. With $\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ taken as ≈ 1.7 × 10⁸yr, the isotopic abundance of ⁹⁸Nb is 1.2 × 10^?10 per cent.