Ethical concerns around inner city walking tours

Walking tours are common practice in urban tourism and are, historically, one of the earliest examples of urban tourism. Due to a rise in the demand for so-called “authentic” experiences in tourism in recent years, there has been a growth in different types of cultural walking tours, particularly in poor neighborhoods of major cities globally. The increase in these tours brings to light a number of questions concerning the ethics of taking people through poorer areas, where relatively vulnerable populations live and work. This paper highlights some of the potential ethical concerns around this type of tourism, while also mentioning the potential benefits.     

Patterns of oxygen isotope depletion,multiple hydrothermal circulation systems,and the cooling history of the Stony Mountain intrusive complex,Colorado

Oxygen isotopic compositions of 27 whole rock and mineral samples from the three intrusive phases of the Stony Mountain stock, San Juan Mountains, Colorado, have been measured and are combined with published analyses to obtain a history of the meteoric water circulation that cooled the intrusions. The order of intrusion was: the Outer Diorite, the Gabbro and the Inner Diorite. The new whole rock data give δ¹⁸O (SMOW) + 1.9 to + 3.7‰ for the Gabbro, and + 0.4 to + 4.9‰ for the Inner Diorite. Five mineral analyses are reported for the Inner Diorite: three feldspars (ranging from + 0.2 to + 4.3), one quartz (+8.2), and one pyroxene (+5.3).All three intrusions are significantly depleted in¹⁸O relative to normal igneous rocks. This depletion occurred by subsolidus exchange of oxygen isotopes, as shown by the correlation between the extent of depletion and the grain size, and by the non-equilibrium¹⁸O concentrations in coexisting minerals. The patterns of¹⁸O depletion, which are complex, suggest that separate hydrothermal circulation systems were set up by the cooling of each intrusion in turn.The minimum water to rock ratio required to effect the observed depletion in the Inner Diorite is approximately 0.18, although the ratio for the total flux was probably much greater. The mineral data show marked¹⁸O depletion in the feldspars and little, if any, depletion in the quartz. Application of oxygen diffusion data for feldspar and quartz leads to the conclusion that the effective temperature for oxygen isotope exchange was below 600°C and above 400°C. Furthermore, these data place constraints on convective cooling times for this intrusion. Minimum times for cooling of the 500-m-diameter Inner Diorite through this temperature range are on the order of 14 to 900 years. For comparison, a maximum time limit of 4000 years would be needed if cooling occurred only by conduction.     

Cerdanya basin geometry and its implication on the Neocene evolution of the Eastern Pyrenees

Cerdanya is a Neogene half-graben basin that lies over the Palaeozoic rocks of the Eastern Pyrenean Axial Zone. Subvertical fault scarps bound the half-graben at the southern and southeastern margins, but Neogene sediments may directly overlap Palaeozoic rocks in the northern margin.Vertical electrical soundings show that the Miocene sequence reaches a maximum thickness of over 700 m and that fine-grained lacustrine deposits from the central part of the basin grade to coarser fluvial deposits toward the margins.Macro- and micro-structural data analyzed in Cerdanya and other related Neogene basins, such as Rosselló, Confient, Capcir and Seu d'Urgell, suggest that they formed as a consequence of transtensile motion along an old northeastern-trending fault. The stress situation favoured sinistral movements along east-trending faults.     

Hydrocarbons in 60 northeast Gulf of Mexico shelf sediments: a preliminary survey

Hydrocarbon results from gas chromatography of 60 recent sediment and 10 benthic algae samples delineate two distinct shelf environments in the northeastern Gulf of Mexico.Sediments off Florida (shell hashes and sands) have moderate amounts of lipids/total sediment (average 113ppm ± 80%) but low hydrocarbon levels (average 3.06 ppm ± 41%). Aliphatic hydrocarbons are dominated by a series of branched or cyclic, unsaturated C₂₅ isomers. The major n-alkane is n-C₁₇. The n-alkane and isoprenoid patterns are consistent with a marine hydrocarbon source.Sediments closer to the Mississippi River (silts and clays) contain large amounts of lipids (average 232 ppm ± 53%) and hydrocarbons (average 11.7 ppm ± 55%) to total sediment. Aliphatic hydrocarbons are mainly odd carbon number high molecular weight n-alkanes, indicating a terrigenous hydrocarbon source. Isoprenoids are present in greater abundance than in sediments off Florida (n-C₁₇/ pristane and n-C₁₈/phytane ratios ~2to 3). Relatively large amounts of n-C₁₆, together with an even distribution of n-alkanes in the range C₁₄–C₂₀ and a substantial unresolved envelope all point to a fossil fuel input to the Mississippi samples.Samples off the Alabama coast show intermediate characteristics.     

Solution-collapse depressions and suspensates in the limnocrenic lake of banyoles (ne Spain)

A high resolution seismic reflection survey in the Banyoles limnocrenic solution lake allowed penetration of dense suspensates occupying cone-like bottom depressions of different size. The depressions result from the dissolution and collapse of underlying Eocene calcareous and gypsiferous materials over which lacustrine sediments of varying thicknesses have accumulated. The suspensates occupying the depressions present three main types of seismic signatures: stratified, semistratified, and transparent. The densities of the suspensates and the water depths of their tops, which fluctuate continuously, vary from one depression to another. The maximum seismically recorded suspensate thickness is 44 m. Morphological and structural features, seismic characters, and variable degrees of hydraulic activity, point to the existence of different stages of maturity in the lake bottom depressions. This work brings new insight on the dynamics and evolution of limnocrenic solution lakes.     

Geophysical fingerprints of hyper-extended,exhumed and embryonic oceanic domains: the example from the Iberia–Newfoundland rifted margins

This study investigates the magnetic and gravity signatures and associated seismic character of hyper-extended, exhumed and embryonic oceanic domains along the conjugate Iberia–Newfoundland rifted margins. As these margins have been drilled down to basement along their distal parts, it is possible to explore and test different geophysical techniques and interpretations. The aims of this work are twofold: (1) to investigate the location and nature of the two main marginal boundaries—the necking zone and the J Anomaly, which define the limits of major domains; and (2) to map the lateral variations of gravity and magnetic signatures and their detailed correlation with seismic data, from the proximal margin until the first unequivocal oceanic magnetic anomaly (e.g. C34 Anomaly). The results point out that the J Anomaly corresponds to a first-order tectono-magmatic boundary, with a basement formed by polyphase magmatism. It marks the boundary between the exhumed mantle domain, with little magmatic additions, from a domain oceanwards that reveals comparable trends, frequencies and a general magnetic pattern at both sides of the Atlantic, suggesting a coeval evolution. We propose that the domain between the J and the C34 Anomalies was formed by an embryonic spreading system, with intermittent budgets of magma, similar to those observed at very slow spreading systems. The J Anomaly may thus correspond to the location of lithospheric breakup though its origin and the nature of the domain oceanwards remains to be constrained.     

“Where to put the spare cash?” Subprime urbanization and the geographies of the financial crisis in the Global South

This article investigates the geographies of subprime urbanization, and by extension, the displacement of 2007–08 financial crisis to the Global South. Previous research examined the formative ways that technological innovations enabled mortgages to deterritorialize and circulate on secondary markets. Less is known about how cities with underdeveloped financial systems and housing markets have been impacted. The case of Tangier, Morocco, is used to argue that the geography of the crisis must be understood as a particular mode of urbanization, subprime urbanization, predicated upon the creation and exploitation of housing submarkets into new geographical frontiers. Subprime urbanization emerged in Tangier in response to the historic contradictions of regional disinvestment in northern Morocco. Weak financial inclusion for local low-income homebuyers led State bureaucrats to increasingly use housing policy to encourage European investment into Moroccan property markets, thereby transforming policy away from improving homeownership access and inclusion toward an urban model centered on the logics of international property speculation.     

Learning to Adapt: Organisational Adaptation to Climate Change Impacts

Analysis of human adaptation to climate change should be based on realistic models of adaptive behaviour at the level of organisations and individuals. The paper sets out a framework for analysing adaptation to the direct and indirect impacts of climate change in business organisations with new evidence presented from empirical research into adaptation in nine case-study companies. It argues that adaptation to climate change has many similarities with processes of organisational learning. The paper suggests that business organisations face a number of obstacles in learning how to adapt to climate change impacts, especially in relation to the weakness and ambiguity of signals about climate change and the uncertainty about benefits flowing from adaptation measures. Organisations rarely adapt ‘autonomously’, since their adaptive behaviour is influenced by policy and market conditions, and draws on resources external to the organisation. The paper identifies four adaptation strategies that pattern organisational adaptive behaviour.     

Stable Atmospheric Boundary Layer Over a Uniform Slope: Some Theoretical Concepts

Theoretical arguments are developed to describe the effects of a uniform slope on the development of the stably stratified atmospheric boundary layer (SBL). A maximum sustainable surface buoyancy flux exists for the SBL overlying a uniform, non-sloping surface. In this study it is shown that the SBL overlying a uniform shallow slope (with gradient of the order of 1:1000) also supports a maximum sustainable buoyancy flux, B _max, but that the value of B _max is influenced by the gradient of the slope, γ. It is demonstrated that in the limit γ → 0, results for the SBL over a horizontal surface are recovered.