Exploring the potential linkages between oil‐field brine reinjection,crystalline basement permeability,and triggered seismicity for the Dagger Draw Oil field,southeastern New Mexico,USA, using hydrologic modeling

We used hydrologic models to explore the potential linkages between oil‐field brine reinjection and increases in earthquake frequency (up to M_d 3.26) in southeastern New Mexico and to assess different injection management scenarios aimed at reducing the risk of triggered seismicity. Our analysis focuses on saline water reinjection into the basal Ellenburger Group beneath the Dagger Draw Oil field, Permian Basin. Increased seismic frequency (>M_d 2) began in 2001, 5 years after peak injection, at an average depth of 11 km within the basement 15 km to the west of the reinjection wells. We considered several scenarios including assigning an effective or bulk permeability value to the crystalline basement, including a conductive fault zone surrounded by tighter crystalline basement rocks, and allowing permeability to decay with depth. We initially adopted a 7 m (0.07 MPa) head increase as the threshold for triggered seismicity. Only two scenarios produced excess heads of 7m five years after peak injection. In the first, a hydraulic diffusivity of 0.1 m² s^?1 was assigned to the crystalline basement. In the second, a hydraulic diffusivity of 0.3 m² s^?1 was assigned to a conductive fault zone. If we had considered a wider range of threshold excess heads to be between 1 and 60 m, then the range of acceptable hydraulic diffusivities would have increased (between 0.1–0.01 m² s^?1 and 1–0.1 m² s^?1 for the bulk and fault zone scenarios, respectively). A permeability–depth decay model would have also satisfied the 5‐year time lag criterion. We also tested several injection management scenarios including redistributing injection volumes between various wells and lowering the total volume of injected fluids. Scenarios that reduced computed excess heads by over 50% within the crystalline basement resulted from reducing the total volume of reinjected fluids by a factor of 2 or more.     

Consuming Ethics: Articulating the Subjects and Spaces of Ethical Consumption

Geography's debates about how to maintain a sense of morally responsible action often emphasise the problematic nature of caring at a distance, and take for granted particular kinds of moral selfhood in which responsibility is bound into notions of human agency that emphasise knowledge and recognition. Taking commodity consumption as a field in which the ethics, morality, and politics of responsibility has been problematised, we argue that existing research on consumption fails to register the full complexity of the practices, motivations and mechanisms through which the working-up of moral selves is undertaken in relation to consumption practices. Rather than assuming that ethical decision‐making works through the rational calculation of obligations, we conceptualise the emergence of ethical consumption as ways in which everyday practical moral dispositions are re‐articulated by policies, campaigns and practices that enlist ordinary people into broader projects of social change. Ethical consumption, then, involves both a governing of consumption and a governing of the consuming self. Using the example of Traidcraft , we present a detailed examination of one particular context in which self‐consciously ethical consumption is mediated, suggesting that ethical consumption can be understood as opening up ethical and political considerations in new combinations. We therefore argue for the importance of the growth of ethical consumption as a new terrain of political action, while also emphasising the grounds upon which ethical consumption can be opened up to normative critique.     

FINGERPRINTING OF ROMAN MINTS USING LASER‐ABLATION MC–ICP–MS LEAD ISOTOPE ANALYSIS*

In this paper we present data to demonstrate the applicability of laser‐ablation MC–ICP–MS isotope analysis to archaeological artefacts, in this case Roman silver coins. The technique requires no chemical preparation, does minimal damage to the sample and yields external reproducibility that is better than conventional TIMS analysis; ²⁰⁷Pb/²⁰⁶Pb =±0.015% 2σ in comparison with ²⁰⁷Pb/²⁰⁶Pb =±0.04% 2σ, respectively. We show that Pb isotope compositions give isotope fingerprints to mints despite the likely reworking of the metal during coin production.     

Mitochondrial DNA from 3000-year old chickens at the Teouma site,Vanuatu

Chickens were part of the Lapita cultural complex, transported into and through the Pacific by prehistoric colonists; as such they can be used as a proxy for tracking prehistoric migration and interaction. The Lapita site of Teouma in Vanuatu is well known for the recovery of complete dentate stamped pots and a cemetery containing the largest collection of Lapita period skeletons ever found. Chicken bones recovered from these excavations provide the first ancient DNA sequences from any commensal organism directly associated with a Lapita context. The ancient mtDNA sequences obtained from two Teouma chicken bones are compared with previously published archaeologically derived ancient DNA sequences to extend our understanding of the spread of chickens in Pacific prehistory. The results also show that the haplogroup E signature was present in very early populations of chickens transported into Remote Oceania. This study also adds to the suite of available data relating to isotopic signatures for commensal animals during the early settlement of Vanuatu and may reveal a different diet for Teouma chickens than those from other early prehistoric assemblages in the Pacific.     

The Gravity of Archaeology

One of the defining features of the material culture of space exploration is the fact that much of it is “out there”: in orbit around celestial bodies and on planetary surfaces. In outer space, we have to rethink the meaning of place. Cartesian coordinates must be replaced with equations of motion to describe the ceaseless movement of heavenly objects in relation to centres of gravity. Archaeological sites in space are not solid condensations of artefacts, hundreds or thousands of years compressed into layers perhaps only centimetres deep. The materials of an archaeological deposit become rather a cloud or swarm. But for both Earth and space, gravity is the structuring force. In this paper I want to reconceptualise archaeological sites according to their position in the gravity well, using dynamical systems and Riemann surfaces. I then consider the Mir space station as an example of a site existing simultaneously on Earth and in orbit, as a preliminary excursion towards a frame of reference that can be used to effectively conduct an archaeology in outer space.     

Oxygen and strontium isotope evidence for mobility in Roman Winchester

Artefacts and burial rites in the late Roman cemetery at Lankhills School, Winchester, southern England, were used by Clarke (1979) to distinguish between local Romano-British individuals and migrants thought to be from the Danube region, a suggestion tested through isotope analysis by Evans et al. (2006a,b). This paper reports strontium (⁸⁷Sr/⁸⁶Sr) and oxygen (δ¹⁸O) isotope data for tooth enamel sampled from a further 40 individuals from more recent excavations on the same site. Results suggest that up to a quarter of the sampled Lankhills individuals were incomers, with several individuals possibly originating from the Hungarian Basin and the Southern Mediterranean. However, there was no clear link between isotopic signature and archaeological origin attribution, suggesting that in many cases burial practice was dictated by factors other than ‘ethnicity’, such as kinship, marriage or cultural and political preferences.     

Reaping the rewards: the potential of well designed methodology,a comment on Vardi et al. (Journal of Archaeological Science 37 (2010) 1716–1724) and Goodale et al. (Journal of Archaeological Science 37 (2010) 1192–1201)

The recent articles by Vardi et al., “Tracing sickle blade levels of wear and discard patterns: a new sickle gloss quantification method” (Journal of Archaeological Science 37 (2010) 1716–1724), and Goodale et al., “Sickle blade life-history and the transition to agriculture: an early Neolithic case study from Southwest Asia” (Journal of Archaeological Science 37 (2010) 1192–1201), are two papers that seek to address interesting archaeological questions through the development of new approaches to measuring the duration of stone tool use. Here comment is made on the fashion in which research design and analytic procedures contribute to limit the capabilities of each of the techniques presented. Whilst the authors support the investigation of novel techniques, in order for the results of any use-wear analysis to be accepted as reliable the methods employed must be demonstrably sound.     

Inequality in Human Resources for Health: Measurement Issues

This article discusses options to allow comparative analysis of inequalities in the distribution of health workers (HWs) across and within countries using a single summary measure of the distribution. Income inequality generally is measured across individuals, but inequalities in the dispersion of HWs must use geographical areas or population groupings as units of analysis. The article first shows how this change of observational unit creates a resolution problem for various inequality indices and then tests how sensitive a simple ratio measure of the distribution of HWs is to changes in resolution. This ratio of inequality is illustrated first with the global distribution of HWs and then with its distributions within Indonesia. The resolution problem is not solved through this new approach, and indicators of inequalities of access to HWs or health services more generally appear not to be comparable across countries. Investigating geographical inequalities over time in one setting is possible but only if the units of analysis remain the same over time.