Urban consolidation and house prices: a case study of Melbourne 1990–2004

This paper explores the links between a strategic policy, urban consolidation, and house prices by examining the changes in the mix of housing and in house price for the period 1991–2004. We contend that urban consolidation could be seen as a source of additional supply, (which might be expected to be felt in lower prices and so contribute to a local policy objective) but also as a stimulus to demand (by developers who could bid up the price of lots where it was understood more housing could be built). Analyses were carried out at the metropolitan and sub-regional scales using correlation tests. The research finds very weak statistical connections, and concludes that this policy has not been associated with price changes.     

Iron and chlorine as guides to stratiform Cu-Co-Au deposits,Idaho Cobalt Belt,USA

The Cu-Co-Au deposits of the Idaho Cobalt Belt are in lithostratigraphic zones of the Middle Proterozoic Yellowjacket Formation characterized by distinctive chemical and mineralogical compositions including high concentrations of Fe (15- > 30 wt. percent Fe₂O₃), Cl (0.1–1.10 wt. percent), and magnetite or biotite (> 50 vol. percent). The Cu-Co-Au deposits of the Blackbird mine are stratabound in Fe-silicate facies rocks that are rich in biotite, Fe, and Cl, but stratigraphically equivalent rocks farther than 10 km from ore deposits have similar compositions. A lower lithostratigraphic zone containing magnetite and small Cu-Co-Au deposits extends for more than 40 km. The Fe-rich strata are probably exhalative units related to mafic volcanism and submarine hot springs, but the origin of the high Cl concentrations is less clear. Former chlorine-rich pore fluids are suggested by the presence of supersaline fluid inclusions, by Cl-rich biotite and scapolite (as much as 1.87 percent Cl in Fe-rich biotite), and by high Cl concentrations in rock samples. Chlorine is enriched in specific strata and in zones characterized by soft-sediment deformation, thus probably was introduced during sedimentation or diagenesis. Unlike some metasedimentary rocks containing scapolite and high Cl, the Yellowjacket Formation lacks evidence for evaporitic strata that could have been a source of Cl. More likely, the Cl reflects a submarine brine that carried Fe, K, and base metals. Strata containing anomalous Fe-K-Cl are considered to be a guide to sub-basins favorable for the occurrence of stratiform base-metal deposits.     

Volcanic ash clouds affecting Northern Europe: the long view

The volcanic ash or ‘tephra’ cloud resulting from the relatively small (volume and VEI) eruption of the Icelandic volcano Eyjafjallajökull in 2010 caused major air travel disruption, at substantial global economic cost. On several occasions in the past few centuries, Icelandic eruptions have created ash and/or sulphur dioxide clouds which were detected over Europe (e.g. Hekla in 1947, Askja in 1875, and Laki in 1783). However, these historical observations do not represent a complete record of events serious enough to disrupt aviation in Europe. The only feasible evidence for this is within the geological tephra record. Ash layers are preserved in bogs and lakes where tephra deposited from the atmosphere is incorporated in the peat/mud. In this article we: 1, introduce the analysis of the Northern European sedimentary tephra record; 2, discuss our findings and modelling results; 3, highlight how these were misinterpreted by the popular media; and 4, use this experience to outline several existing problems with current tephra studies and suggest agendas for future research.     

Simulation Chamber Studies of the Atmospheric Oxidation of 2-Methyl-3-Buten-2-ol: Reaction with Hydroxyl Radicals and Ozone Under a Variety of Conditions

This article presents a complete study of the diurnal chemical reactivity of the biogenic volatile organic compound (BVOC), 2-methyl-3-buten-2-ol (MBO) in the troposphere. Reactions of MBO with OH and with ozone were studied to analyse the respective parts of both processes in the global budget of MBO atmospheric reactivity. They were investigated under controlled conditions for pressure (atmospheric pressure) and temperature (298 ± 2 K) using three complementary European simulation chambers. Reaction with OH radicals was studied in the presence of and in the absence of NO _x . The kinetic study was carried out by relative rate study using isoprene as a reference. The rate constant found for this reaction was molecule⁻¹ cm³ s⁻¹. FTIR spectroscopy, DNPH- and PFBHA-derivatisation analyses were performed for reactions with both OH radicals and ozone. In both reactions, the hydroxycarbonyl compound, 2-hydroxy-2-methylpropanal (HMPr) was positively identified and quantified, with a yield of in the reaction with OH, and a yield of and 0.84 ± 0.08 in the reaction with ozone under dry (HR < 1%) and humid conditions (HR = 20%–30%). A primary production of two other carbonyl compounds, acetone , and formaldehyde was found in the case of the dry ozonolysis experiments. Under humid conditions, only formaldehyde was co-produced with HMPr as a primary carbonyl compound, with a yield of . For the reaction with OH, three other carbonyl compounds were detected, acetone , formaldehyde and glycolaldehyde . In addition some realistic photo-oxidation experiments were performed to understand in an overall way the transformations of MBO in the atmosphere. The realistic photo-oxidation experiments were conducted in the EUPHORE outdoor simulation chamber. It was found that this compound is a weak secondary aerosol producer (less than 1% of the carbon balance). But it was confirmed that it is a potentially significant source of acetone, Δ[Acetone]/Δ[MBO] = 0.45. With our experimental conditions ([MBO]₀ = 200 ppb, [NO]o = 50 ppb), an ozone yield of Δ[O₃]/Δ[MBO] = 1.05 was found.     

Numerical modelling of suspended sediments

The turbulent advection-diffusion mathematical model in three-dimensional space is solved by a mixed finite element finite difference method. Linear finite elements in the vertical direction and central finite differences in the horizontal directions are used coupled with the Galerkin error minimization procedure. The integration in time is performed in fractional steps (one explicit one implicit) by splitting the differential operator. The method is illustrated by application to the three-dimensional movement of suspended sediment. Its accuracy is checked by comparison to analytical solutions and its efficiency is gauged relative to finite elements and implicit finite difference solutions for two-dimensional suspended sediment transport over a dredged channel.     

Navigating the Complex Trade-Offs of Pesticide Use on Santa Cruz Island,Galapagos

Pesticide use by farmers on Santa Cruz Island, Galapagos—a perceived adaptation to changing ecological and economic dynamics—has the potential to lead to environmental degradation in an area that is known and valued worldwide for its biodiversity. We survey Santa Cruz farmers to understand motivations for and concerns about pesticide use on the island. Results from farmer surveys are supplemented with interview data to develop the case study of pesticide use on Santa Cruz Island. We then apply a “complex trade-off” framework to explore and navigate the tensions between conservation and livelihoods. We conclude by elaborating the implementation of a participatory certification system, the Participatory Guarantee System, as a possible path for reconciling trade-offs in Santa Cruz, Galapagos.     

Scoria cone formation through a violent Strombolian eruption: Irao Volcano, SW Japan

Scoria cones are common volcanic features and are thought to most commonly develop through the deposition of ballistics produced by gentle Strombolian eruptions and the outward sliding of talus. However, some historic scoria cones have been observed to form with phases of more energetic violent Strombolian eruptions (e.g., the 1943–1952 eruption of Parícutin, central Mexico; the 1975 eruption of Tolbachik, Kamchatka), maintaining volcanic plumes several kilometers in height, sometimes simultaneous with active effusive lava flows. Geologic evidence shows that violent Strombolian eruptions during cone formation may be more common than is generally perceived, and therefore it is important to obtain additional insights about such eruptions to better assess volcanic hazards. We studied Irao Volcano, the largest basaltic monogenetic volcano in the Abu Monogenetic Volcano Group, SW Japan. The geologic features of this volcano are consistent with a violent Strombolian eruption, including voluminous ash and fine lapilli beds (on order of 10^?1 km³ DRE) with simultaneous scoria cone formation and lava effusion from the base of the cone. The characteristics of the volcanic products suggest that the rate of magma ascent decreased gradually throughout the eruption and that less explosive Strombolian eruptions increased in frequency during the later stages of activity. During the eruption sequence, the chemical composition of the magma became more differentiated. A new K–Ar age determination for phlogopite crystallized within basalt dates the formation of Irao Volcano at 0.4?±?0.05 Ma.     

Relationships between volcano distribution, crustal structure, and P-wave tomography: an example from the Abu Monogenetic Volcano Group, SW Japan

Achieving an understanding of the nature of monogenetic volcanic fields depends on identification of the spatial and temporal patterns of volcanism in these fields, and their relationships to structures mapped in the shallow crust and inferred in the deep crust and mantle through interpretation of geophysical data. We investigate the spatial and temporal distributions of volcanism in the Abu Monogenetic Volcano Group, Southwest Japan, and compare these distributions to fault and seismic data in the brittle crust, and P-wave tomography of the crust and upper mantle. Essential characteristics of the volcano distribution are extracted by a nonparametric kernel method using an algorithm to estimate anisotropic bandwidth. Overall, E-W elongate smooth modes in spatial density are identified that are consistent with the spatial extent of P-wave velocity anomalies in the lower crust and upper mantle, supporting the idea that the spatial density map of volcanic vents reflects the geometry of a mantle diapir. While the number of basalt eruptions decreased after 0.2 Ma, andesite eruptions increased and overall volume eruption rate is approximately steady-state. Estimated basalt supply to the lower crust is also constant. This observation and the spatial distribution of volcanic vents suggest stability of magma productivity and essentially constant two-dimensional size of the source mantle diapir since 0.46 Ma.