Disaster prevention,disaster preparedness and local community resilience within the context of disaster risk management in Cameroon

This paper presents a simulation of three components of near-field ground shaking recorded during the main shock at three stations of the September 16, 1978, Tabas (M _w = 7.4), Iran, earthquake, close to the causative fault. A hybrid method composed of a discrete wavenumber method developed by Bouchon (Bouchon in Bull Seismol Soc Am 71:959–971, 1981; Cotton and Coutant in Geophys J Int 128:676–688, 1997) and a stochastic finite-fault modeling based on a dynamic corner frequency proposed by Motazedian and Atkinson (Bull Seismol Soc Am 95:995–1010, 2005), modified by Assatourians and Atkinson (Bull Seismol Soc Am 97:935–1949, 2007), is used for generating the seismograms at low (0.1–1.0 Hz) and high frequencies (1.0–20.0 Hz), respectively. The results are validated by comparing the simulated peak acceleration, peak velocity, peak displacement, Arias intensity, the integral of velocity squared, Fourier spectrum and acceleration response spectrum on a frequency-by-frequency basis, the shape of the normalized integrals of acceleration and velocity squared, and the cross-correlation with the observed time-series data. Each characteristic is compared on a scale from 0 to 10, with 10 being perfect agreement. Also, the results are validated by comparing the simulated ground motions with the modified Mercalli intensity observations reported by reconnaissance teams and showed reasonable agreement. The results of the present study imply that the damage distribution pattern of the 1978 Tabas earthquake can be explained by the source directivity effect.     

Profiling of dissolved organic compounds in the oil sands region using complimentary liquid–liquid extraction and ultrahigh resolution Fourier transform mass spectrometry

Understanding and characterizing organics in aquatic environments is a great challenge for environmental monitoring, especially for the oil sands industry due to the complexity and potential toxicity of dissolved organics in water. To date, significant efforts have been made in investigating the toxicity of naphthenic acids, although other compounds may also contribute to the toxicity of oil sands process-affected water (OSPW). Here, we present a case study showing a systematic approach for profiling the organic composition of OSPW and environmental water samples by concentrating and separating dissolved organics through complementary liquid–liquid extractions followed by positive- or negative-ion mode ultrahigh resolution mass detection. Our comparative investigation shows clear differences in the composition of dissolved organics (homologues particularly) not only between OSPW samples and environmental water samples, but also differences among oil sands operators. Sulfur-containing compounds (especially the SO _n classes) appear to have great potential to be used for evaluating the impact of OSPW, while our understanding of oxygen-only containing compounds should not be limited to O₂ (i.e., classic naphthenic acids), but rather can be broadened to include many other compound classes (for instance O _n , n = 1–9). Systematic profiling of water samples should be more widely implemented for monitoring the origin and transport of organics in aquatic ecosystems of the oil sands development region, northeastern Alberta, Canada.     

Property speculation,global capital,urban planning and financialisation: Sydney Boom,Sydney Bust redux

In this ‘Thinking Space’ essay we revisit Maurie Daly’s 1982 book Sydney Boom, Sydney Bust, fuelled by concern for how Australian cities are being transformed by financialised real estate. Daly's insights remain highly relevant to Sydney and other cities around Australia and the world today. Poorly planned densification, inflated property markets, land speculation, and housing poverty are all outcomes of the (global) capitalist intersection of finance and land in Australia. The overwriting of Aboriginal country with colonial-capitalist systems of land ownership set in train a process of land and housing booms, bubbles and busts that are better understood by their circular continuity rather than as a set of ephemeral ruptures. It is the property and finance system itself, rather than any ruptures to it, that reproduces unequal and alienating social relations. Researchers investigating property speculation, global capital, urban planning and financialisation, we argue, ought to revisit this key text to inform their contemporary analyses. Moreover, those wielding power over Australian urban affairs would do well to read it too, lest its lessons be ignored for another generation.     

Quasi-shear wave ray tracing by wavefront construction in 3-D, anisotropic media

Wavefront construction (WFC) methods provide robust tools for computing ray theoretical traveltimes and amplitudes for multivalued wavefields. They simulate a wavefront propagating through a model using a mesh that is refined adaptively to ensure accuracy as rays diverge during propagation. However, an implementation for quasi-shear (qS) waves in anisotropic media can be very difficult, since the two qS slowness surfaces and wavefronts often intersect at shear-wave singularities. This complicates the task of creating the initial wavefront meshes, as a particular wavefront will be the faster qS-wave in some directions, but slower in others. Analogous problems arise during interpolation as the wavefront propagates, when an existing mesh cell that crosses a singularity on the wavefront is subdivided. Particle motion vectors provide the key information for correctly generating and interpolating wavefront meshes, as they will normally change slowly along a wavefront. Our implementation tests particle motion vectors to ensure correct initialization and propagation of the mesh for the chosen wave type and to confirm that the vectors change gradually along the wavefront. With this approach, the method provides a robust and efficient algorithm for modeling shear-wave propagation in a 3-D, anisotropic medium. We have successfully tested the qS-wave WFC in transversely isotropic models that include line singularities and kiss singularities. Results from a VTI model with a strong vertical gradient in velocity also show the accuracy of the implementation. In addition, we demonstrate that the WFC method can model a wavefront with a triplication caused by intrinsic anisotropy and that its multivalued traveltimes are mapped accurately. Finally, qS-wave synthetic seismograms are validated against an independent, full-waveform solution.     

Spatial analysis of gastric cancer morbidity in regions of rapid urbanization: a case study in Xiamen,China

This paper is purposed to detect the spatial laws of gastric cancer in the rapid urbanization area and analyze relationships between gastric cancer and urbanization. Gastric cancer incidence data in Xiamen between 2006 and 2009 was collected from Xiamen CDC (Centre of Disease Control and Prevention). Urbanization age of Xiamen Island was calculated from remote images and terrain maps. Analysis results showed that 995 gastric cancer cases, accounting for 61.64 % was in Xiamen island, compared with 619 cases, accounting for 38.36 % outside. The average gastric cancer incidence was 32.98/1000,000 in Xiamen Island, compared to 16.13/1000,000 outside. The top ten sub-districts of gastric cancer all located in Xiamen Island, and urban areas have as more than twice gastric cancer incidence as rural area, with 28.62/100,000. The most likely spatial cluster of gastric cancer was Xiamen Island. Correlation analysis results indicated the urbanization age and spatial cluster degree had a significantly positive correlation relationship. Rapid urbanization in Xiamen changed the environment, namely acquired factors including land use change, air–water–soil pollution, less activity, electromagnetic radiation and contaminated sea foods. These are risk factors of gastric cancer. This research indicated that Xiamen Island was prevalent of gastric cancer with a positive correlation with urbanization age.     

Application of grouped detrital zircon analyses to determine provenance and closely approximate true depositional age: Early Cretaceous McMurray-Clearwater succession,Canada

In the Lower CretaceousMcMurray-Clearwater succession of the intracontinental Alberta Foreland Basin,Canada,detrital zircon U-Pb geochronology samples(referred to herein as DZ samples)have been used to interpret the strata as representing a paleo-continental-scale drainage system.However,the majority of DZ samples are relatively small(n≈90–100),and syndepositional DZ(i.e.,crystallization age<5 Ma older than depositional age)are rare.This has forced a reliance on dinocysts with long stratigraphic ranges to chronostratigraphically subdivide the McMurray-Clearwater succession rather than employing maximum depositional ages(MDAs)derived from DZ samples.Herein,43 DZ samples(taken from20 subsurface cores)are assigned to 1 of 5 stratigraphic intervals,and in each stratigraphic interval all associated DZ samples are combined to produce a grouped DZ sample.Analysis and comparison of individual and grouped DZ samples are used to(1)assess variability in provenance through time and space,and(2)assess the accuracy of chronostratigraphically subdividing the succession using MDAs.Along the main paleo-drainage axis,a comparison of dissimilarity between DZ samples from the same stratigraphic interval,as well as between stratigraphic intervals,reveals increasing average dissimilarity between individual DZ samples and their respective grouped DZ samplewith increasing spatial separation of samples.These data indicate that in the McMurray Depocenter some sediment is sourced from local tributaries,leading to geographical provenance variability.CalculatedMDAs for all 43 DZ samples and groupedMDAs(gMDAs)for the 5 grouped DZ samples are compared to an ash-derived absolute age and existing biostratigraphy.In theMcMurray Formation,comparison of MDAs to gMDAs shows that in basins with rare syndepositional DZ,the gMDA method improved depositional age estimates by transforming low-confidence MDAs(e.g.,youngest single grains)into high-confidence(multi-grain)gMDAs.In the Clearwater Formationwhere syndepositional DZ are plentiful(i.e.,>5%of the total DZ population),calculating maximumlikelihood ages fromgrouped DZ samples avoids negatively biased(i.e.,too young)MDAs.We suggest grouped DZ samples and the gMDA method be used in systems with multiple DZ samples from a well-defined stratigraphic interval as a means of assessing variability in provenancewithin a depositional system and for improving estimates of depositional ages using DZ.