Mechanism of the 1996–97 non-eruptive volcano-tectonic earthquake swarm at Iliamna Volcano,Alaska

A significant number of volcano-tectonic (VT) earthquake swarms, some of which are accompanied by ground deformation and/or volcanic gas emissions, do not culminate in an eruption. These swarms are often thought to represent stalled intrusions of magma into the mid- or shallow-level crust. Real-time assessment of the likelihood that a VT swarm will culminate in an eruption is one of the key challenges of volcano monitoring, and retrospective analysis of non-eruptive swarms provides an important framework for future assessments. Here we explore models for a non-eruptive VT earthquake swarm located beneath Iliamna Volcano, Alaska, in May 1996–June 1997 through calculation and inversion of fault-plane solutions for swarm and background periods, and through Coulomb stress modeling of faulting types and hypocenter locations observed during the swarm. Through a comparison of models of deep and shallow intrusions to swarm observations, we aim to test the hypothesis that the 1996–97 swarm represented a shallow intrusion, or “failed” eruption. Observations of the 1996–97 swarm are found to be consistent with several scenarios including both shallow and deep intrusion, most likely involving a relatively small volume of intruded magma and/or a low degree of magma pressurization corresponding to a relatively low likelihood of eruption.     

Cosmogenic <Superscript>10</Superscript>Be-derived denudation rates of the Eastern and Southern European Alps

Denudation rates from cosmogenic ¹⁰Be measured in quartz from recent river sediment have previously been used in the Central Alps to argue that rock uplift occurs through isostatic response to erosion in the absence of ongoing convergence. We present new basin-averaged denudation rates from large rivers in the Eastern and Southern European Alps together with a detailed topographic analysis in order to infer the forces driving erosion. Denudation rates in the Eastern and Southern Alps of 170–1,400 mm ky⁻¹ are within a similar range to those in the Central Alps for similar lithologies. However, these denudation rates vary considerably with lithology, and their variability generally increases with steeper landscapes, where correlations with topographic metrics also become poorer. Tertiary igneous rocks are associated with steep hillslopes and channels and low denudation rates, whereas pre-Alpine gneisses usually exhibit steep hillslopes and higher denudation rates. Molasse, flysch, and schists display lower mean basin slopes and channel gradients, and, despite their high erodibility, low erosion rates. Exceptionally low denudation rates are also measured in Permian rhyolite, which has high mean basin slopes. We invoke geomorphic inheritance as a major factor controlling erosion, such that large erosive glaciers in the late Quaternary cold periods were more effective in priming landscapes in the Central Alps for erosion than in the interior Eastern Alps. However, the difference in tectonic evolution of the Eastern and Central Alps potentially adds to differences in their geomorphic response; their deep structures differ significantly and, unlike the Central Alps, the Eastern Alps are affected by ongoing tectonic influx due to the slow motion and rotation of Adria. The result is a complex pattern of high mountain erosion in the Eastern Alps, which has evolved from one confined to the narrow belt of the Tauern Window in late Tertiary time to one affecting the entire underthrust basement, orogenic lid, and parts of the Southern Alps today.     

Uranium series disequilibria in the sedimentary uranium deposit at Yeelirrie,Western Australia

The weighted mean values of the ²³⁴U/²³⁸U and the ²³⁰Th/²³⁴U ratios in ore samples collected above the modern water table of the Yeelirrie uranium deposit in Western Australia are 1.38 ± 0.10 and 0.83 ± 0.28, respectively. The relatively larger variability in the latter ratio is evidence for the translocation of uranium subsequent to deposition. Daughter product separation is due to differences in the mobilities of the thorium and uranium species. Factors involved in interpreting the observed ratios, in terms of the dynamics of the accumulation of the deposit, are assessed in terms of an open system model. The observed disequilibria provide a quantitative basis for the evaluation of hypotheses developed from geological and other considerations.     

WTO fisheries subsidies negotiations: implications for fisheries access arrangements and sustainable management

The paper considers the WTO negotiations on fisheries subsidies and the implications that envisaged disciplines will have on coastal developing countries. This is considered in relation to fisheries access agreements in the Central and Western Pacific where several least developed but resource rich island states such as Kiribati and Tuvalu are highly exposed to the risks associated with new WTO fisheries subsidies disciplines that do not consider their particular vulnerabilities. The paper considers some of the issues that coastal developing countries should incorporate into their emerging negotiating positions at the WTO. State-to-Sate fisheries access agreements which are often highly subsidised but where fishing vessel owners pay the equivalent of lump sum tax are paradoxically, the least distortionary and damaging to the environment. Strategies for managing the possible new disciplines are considered.     

Confirming regional 1 cm differential geoid accuracy from airborne gravimetry: the Geoid Slope Validation Survey of 2011

A terrestrial survey, called the Geoid Slope Validation Survey of 2011 (GSVS11), encompassing leveling, GPS, astrogeodetic deflections of the vertical (DOV) and surface gravity was performed in the United States. The general purpose of that survey was to evaluate the current accuracy of gravimetric geoid models, and also to determine the impact of introducing new airborne gravity data from the ‘Gravity for the Redefinition of the American Vertical Datum’ (GRAV-D) project. More specifically, the GSVS11 survey was performed to determine whether or not the GRAV-D airborne gravimetry, flown at 11 km altitude, can reduce differential geoid error to below 1 cm in a low, flat gravimetrically uncomplicated region. GSVS11 comprises a 325 km traverse from Austin to Rockport in Southern Texas, and includes 218 GPS stations ( $\sigma _{\Delta h }= 0.4$ cm over any distance from 0.4 to 325 km) co-located with first-order spirit leveled orthometric heights ( $\sigma _{\Delta H }= 1.3$ cm end-to-end), including new surface gravimetry, and 216 astronomically determined vertical deflections $(\sigma _{\mathrm{DOV}}= 0.1^{\prime \prime })$ . The terrestrial survey data were compared in various ways to specific geoid models, including analysis of RMS residuals between all pairs of points on the line, direct comparison of DOVs to geoid slopes, and a harmonic analysis of the differences between the terrestrial data and various geoid models. These comparisons of the terrestrial survey data with specific geoid models showed conclusively that, in this type of region (low, flat) the geoid models computed using existing terrestrial gravity, combined with digital elevation models (DEMs) and GRACE and GOCE data, differential geoid accuracy of 1 to 3 cm (1 $\sigma )$ over distances from 0.4 to 325 km were currently being achieved. However, the addition of a contemporaneous airborne gravity data set, flown at 11 km altitude, brought the estimated differential geoid accuracy down to 1 cm over nearly all distances from 0.4 to 325 km.     

A Review of “Reconstructing Kobe: The Geography of Crisis and Opportunity”

This paper presents reflections on a research project in women's health, providing both substantive findings surrounding tanning and social status and methodological recommendations for future research. The project under review utilized a picture-elicited storytelling method to: a) understand how women link tanned, bronzed skin to health, status, and attractiveness; and b) test the effectiveness of picture-elicited storytelling as a research method. The project found that, when tanning, women use their bodies to inscribe the social norm of the bronzed aesthetic. While women indicate considerable knowledge of the health dangers of tanning, they continue to link tanned skin to beauty, status, and attractiveness. Further, the research project found that the use of picture-elicited storytelling as a method is potentially powerful but requires considerable attention to concerns of power and representation on the part of the research team.     

Temperature Impacts on <Emphasis Type="Italic">Eurytemora carolleeae</Emphasis> Size and Vital Rates in the Upper Chesapeake Bay in Winter

The copepod Eurytemora carolleeae dominates vernal zooplankton biomass in the Chesapeake Bay estuarine turbidity maximum (ETM) region, where it is an important prey item for larval anadromous fish. Although there have been several zooplankton studies in the Chesapeake Bay ETM focused on spring, the importance of winter zooplankton populations for establishing these vernal conditions has not been investigated. We examined the abundance, distribution, and individual sizes of E. carolleeae in winter of 2007 and 2008 and we investigated the potential impact of varying winter conditions and rising winter temperatures on Eurytemora female carbon content, egg production rate, and generation time. We found higher abundances and larger individuals in the colder 2007 than in 2008 under similar freshwater flow conditions. Empirical estimates showed that overall zooplankton productivity was higher in 2007 than in 2008. Published recruitment indices for anadromous fish including white perch and striped bass were higher in 2007 than in 2008 in the study region. Based on these findings, we hypothesize that colder conditions resulted in larger individuals and therefore increased prey biomass available to larval fish. We further hypothesize that rising winter water temperatures will negatively impact trophic transfer of primary production to copepods and ultimately to fish.     

Red Sea Intermediate Water in the source regions of the Agulhas Current

Red Sea Intermediate Water (RSIW) has been shown to move down the Agulhas Current as distinct lenses. It has been assumed that this intermittency is the result of variable input. To clarify and quantify the nature of RSIW contributions from the source regions of the Agulhas Current observations at 15 hydrographic sections were examined using a multi-parameter analysis. In the northern Mozambique Channel RSIW is found to be layer-like, but with patches of distinctly different contributions. In the southern part of the channel the layer-like distribution disappears with RSIW mostly confined within anticyclonic and cyclonic eddies exhibiting varying maximum contributions ranging from 15–20% to 25–30% purity. Net transports across the channel ranged from ?0.45 to ?0.7 Sv. At the southern tip of Madagascar RSIW contributions exhibited similar purity variability ranging from 10–15% to 15–20%. The net southward transport of RSIW in the East Madagascar Current displayed an even greater variability due to changes in the flux of the undercurrent ranging from negligible to ?0.3 Sv. Indications therefore were that the transport of RSIW to the Agulhas Current occurs in both cyclones and anti-cyclones through the Mozambique Channel whilst from the East Madagascar Current it is mostly confined to anti-cyclones. This variability in the inflow was also reflected in the northern part of the Agulhas Current proper. The maximum contributions of RSIW range here from 10–15% to 20–25% purity and net transports from ?0.75 to ?1.39 Sv off Durban. As it was east of Madagascar RSIW was mostly confined to the slope.     

Multiobjective analysis of a public wellfield using artificial neural networks

As competition for increasingly scarce ground water resources grows, many decision makers may come to rely upon rigorous multiobjective techniques to help identify appropriate and defensible policies, particularly when disparate stakeholder groups are involved. In this study, decision analysis was conducted on a public water supply wellfield to balance water supply needs with well vulnerability to contamination from a nearby ground water contaminant plume. With few alternative water sources, decision makers must balance the conflicting objectives of maximizing water supply volume from noncontaminated wells while minimizing their vulnerability to contamination from the plume. Artificial neural networks (ANNs) were developed with simulation data from a numerical ground water flow model developed for the study area. The ANN-derived state transition equations were embedded into a multiobjective optimization model, from which the Pareto frontier or trade-off curve between water supply and wellfield vulnerability was identified. Relative preference values and power factors were assigned to the three stakeholders, namely the company whose waste contaminated the aquifer, the community supplied by the wells, and the water utility company that owns and operates the wells. A compromise pumping policy that effectively balances the two conflicting objectives in accordance with the preferences of the three stakeholder groups was then identified using various distance-based methods.