John Dewey’s metaphysical ground-map and its implications for geographical inquiry

John Dewey was the most significant and influential thinker associated with the American philosophy commonly known as pragmatism. Drawing on Dewey’s writings as well as the work of Deweyan scholars, I endeavor to explain Dewey’s unique contribution to philosophical discourse and how his overlooked scholarship can inform geographical inquiry. After an introduction, I provide a background understanding of Dewey and his context as well as the use of his philosophy in geography and sociology. I then turn to an exposition of Dewey’s metaphysics which are the heart of his philosophy. My discussion breaks his metaphysics into four parts: nature and continuity, contingency and change, situated sociality, and transaction. The subsequent section argues for Dewey’s distinction and value by arguing a particular implication of Dewey’s work for geography—a reconceptualization of place—and more general propositions about what a Dewey-informed geography would, at minimum, entail. A brief conclusion summarizes the Deweyan vision in the context of geographical inquiry.     

John Wood 2: Planning and Paying for His Town Plans

Abstract

John Wood, the 19th-century urban cartographer, surveyed almost 150 towns spread widely across Great Britain. His detailed large-scale plans are an astounding achievement. In light of this, two questions are posed: did he have a strategy that guided the places which he surveyed; and how did he pay for his work, given that so few copies of his plans appear to have been produced for sale – or at least to have survived.     

75th anniversary of strong motion observation—A historical review

This review describes the experience accumulated in the field of recording earthquake motions up to the early 1900s, and then it discusses the key players who contributed to the first successful strong motion observation program in earthquake engineering in the 1930s. It begins by summarizing the accomplishments of the preceding seismological observations, which provided the stepping-stone ideas on how to construct the first strong motion accelerograph. Next, it describes the lack of optimism among the engineers in the early 1900s, who doubted that structural response could ever be calculated for irregular earthquake ground motion—this was, of course, half a century before the appearance of fast digital computers—but also their realization that something needed to be done to reduce the hazards from earthquakes. The roles of the two pioneers Kyoji Suyehiro and John Freeman, whose vision, leadership, and perseverance launched the strong motion observation program in 1932, are then briefly discussed. Finally, the mechanical characteristics of the first strong motion accelerograph are outlined. The review is completed by illustrating the growth of the strong motion observation programs in selected seismic areas of the world and the fruits of these programs—the cumulative number of uniformly processed strong motion records in southern California.     

Saltwater intrusion modeling in heterogeneous confined aquifers using two-relaxation-time lattice Boltzmann method

This study develops a lattice Boltzmann method (LBM) with a two-relaxation-time collision operator (LTRT) to solve saltwater intrusion problems. A directional-speed-of-sound (DSS) technique is introduced to take into account the hydraulic conductivity heterogeneity and discontinuity, as well as the velocity-dependent dispersion coefficient. The forcing terms in the LTRT model are customized in order to recover the density-dependent groundwater flow and mass transport equations. Using the LTRT with the squared DSS achieves at least second-order accuracy. The LTRT results are verified with Henry’s analytical solution as well as compared with several numerical examples and modified Henry problems that consider heterogeneous hydraulic conductivity and velocity-dependent dispersion. The numerical results show good agreement with the Henry analytical solution and with the numerical solutions obtained by other numerical methods.     

Modeling outflow from the Ernest Henry Fe oxide Cu–Au deposit: implications for ore genesis and exploration

The Ernest Henry Fe oxide Cu–Au (IOCG) deposit (>ca. 1.51 Ga) is hosted by breccia produced during the waning stages of an evolving hydrothermal system that formed a number of tens of metres to a kilometre scale, pre- and syn-ore alteration halos, although no demonstrable patterns have been attributed to fluids expelled through the outflow zones. However, the recognition of a population of hypersaline fluid inclusions representing the ‘spent’ fluids after Cu–Au deposition at Ernest Henry provides the basis to model the geochemical characteristics of the deposit's outflow zones. Geochemical modeling at 300 °C was undertaken at both high and low fluid/rock ratios via FLUSH models involving three host rock types: (1) granite, (2) calc–silicate rock, and (3) graphitic schist. In models run at high fluid/rock ratios, all rock types are essentially fluid-buffered, and produce an albite–quartz–hematite–barite-rich assemblage, although in low fluid–rock environments, the pH, redox, and geochemical character of the host rock exerts a greater influence on the mineralogy of the alteration assemblages (e.g., andradite, Fe–chlorite, and magnetite). Significant sulphide mineralization was predicted in graphitic schist where sphalerite occurred in both low- and high-porosity models, which indicates the possibility of an association between high-temperature IOCG mineralization and lower temperature base metal mineralization.Cooling experiments (from 300 to 100 °C) using the ‘spent fluids’ predict early high-T (300–200 °C) Na-, Ca-, Fe-, and Mn-rich, magnetite-bearing hydrothermal associations, whereas with cooling to below 200 °C, and with progressive fluid–rock interaction, the system produces rhodochrosite-bearing, hematite–quartz–muscovite–barite-rich assemblages. These results show that the radical geochemical and mineralogical changes associated with cooling and progressive fluid influx are likely to be accompanied by major transformations in the geophysical expression (e.g., spectral and magnetic character) of the alteration in the outflow zone, and highlight the potential link between magnetite- and hematite-bearing IOCG hydrothermal systems.     

Fluid dispersion effects on density-driven thermohaline flow and transport in porous media

This study introduces the dispersive fluid flux of total fluid mass to the density-driven flow equation to improve thermohaline modeling of salt and heat transports in porous media. The dispersive fluid flux in the flow equation is derived to account for an additional fluid flux driven by the density gradient and mechanical dispersion. The coupled flow, salt transport and heat transport governing equations are numerically solved by a fully implicit finite difference method to investigate solution changes due to the dispersive fluid flux. The numerical solutions are verified by the Henry problem and the thermal Elder problem under a moderate density effect and by the brine Elder problem under a strong density effect. It is found that increment of the maximum ratio of the dispersive fluid flux to the advective fluid flux results in increasing dispersivity for the Henry problem and the brine Elder problem. The effects of the dispersive fluid flux on salt and heat transports under high density differences and high dispersivities are more noticeable than under low density differences and low dispersivities. Values of quantitative indicators such as the Nusselt number, mass flux, salt mass stored and maximum penetration depth in the brine Elder problem show noticeable changes by the dispersive fluid flux. In the thermohaline Elder problem, the dispersive fluid flux shows a considerable effect on the shape and the number of developed fingers and makes either an upwelling or a downwelling flow in the center of the domain. In conclusion, for the general case that involves strong density-driven flow and transport modeling in porous media, the dispersive fluid flux should be considered in the flow equation.