Flood Fatalities in Australia, 1788-1996     

Lucinda Coates 《The Australian geographer》1999,30(3):391-408

Information on fatalities from flooding in Australia has been compiled from newspapers, historical accounts, and government and scientific reports. Records covering 1788 to 1996 indicate that at least 2213 persons have been killed in floods in Australia. The overall decadal death rate has decreased from 23.98 per 100 000 population in the 1800s to 0.04 per 100 000 in the 1990s. The greatest number of fatalities has occurred in New South Wales but, taking population into account, Queensland has been the most vulnerable state historically as, more recently, has been the Northern Territory. Most fatalities have occurred during February, and amongst males (80.6 per cent). The overall male:female death and death-rate ratios are both 4:1. Whereas the male:female death-rate ratio has fluctuated over time from 10:1 to 1:1, it does not approach equality. Most fatalities (38.5 per cent) have occurred through attempts to cross creeks, bridges or roads in times of flood. Another 31.5 per cent of victims were in houses-the majority awaiting rescue, or simply unaware of the flood. Of the total known deaths, work-related fatalities have accounted for 12.4 per cent, and recreational pursuits for 5.7 per cent.  相似文献   

Ontogenetic shifts in feeding habits of orangemouth weakfish (Cynoscion xanthulus): From estuarine benthic feeder to marine nektivore top predator     

Víctor M. Muro-Torres  Felipe Amezcua  Lucinda Green  Jorge Payan  Eduardo F. Balart-Páez  Felipe Amezcua-Linares 《Marine Ecology》2023,44(1):e12735

Orangemouth weakfish is a highly important commercial and game fish species in the Tropical Eastern Pacific. However, studies assessing changes in its trophic ecology relevant to size, habitat (estuarine or marine), sex, and season are non-existent. We assessed its feeding habits and trophic position (TP) according to the aforementioned factors. Its dietary breadth was composed of 33 types of prey. The feeding habits and isotopic values (δ¹⁵N and δ¹³C) registered differences between sizes and habitat, indicating ontogenetic changes in habitat as well as TP, as small organisms (TP 3.1) inhabited the estuarine area, feeding on benthic and demersal organisms, whilst large individuals (TP 4.1) were found in the marine environment, preying on nektonic fauna. No differences were found according to sex or season. The isotopic niche showed that the different sizes of this species are generalist consumers with a clear separation between them and between habitats, as estuarine juvenile and preadult organisms have a larger isotopic niche than adult marine organisms, being an opportunist tertiary estuarine consumers during their early stages, and a top marine predator during the adult phase.  相似文献   

Observations of active-chromosphere stars – V. A photometric study of the RS CVn system CF Tuc (HD 5303)     

G. J. Anders  ‡  D. W. Coates  ‡  K. Thompson‡  J. L. Innis†‡ 《Monthly notices of the Royal Astronomical Society》1999,310(2):377-386

The Wilson–Devinney program is used to model 27 light curves (our own and others) for CF Tuc. We find new parameters for the binary system, and estimate the longitudes and radii of the spots on the cooler secondary star. We also find a strong tendency for spots on the cooler star to appear in a limited range of longitudes, rather than to migrate fairly rapidly as for other RS CVn systems. There is evidence that the mean light level of the cooler star is varying cyclically.
The orbital period clearly changes discontinuously. We discuss this, and the apparently cyclic variations in mean light level, in relation to the model proposed by Applegate.  相似文献   

Localized Sulfate-Reducing Zones in a Coastal Plain Aquifer   总被引：2，自引：0，他引：2  

Craig J. Brown  John D. Coates  Martin A.A. Schoonen 《Ground water》1999,37(4):505-516

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On convective turbulence and the influence of rotation     

M.J. Coates  G.N. Ivey 《Dynamics of Atmospheres and Oceans》1997,25(4):217-232

A series of experiments were performed in a rotating cylindrical tank over a wide range of rotation rates in which convective turbulence was generated by a bottom-mounted heated plate in both homogeneous and stratified fluids. Measurements were made of the turbulent velocities in all three axes over the full depth of the chamber, and of the temperatures at the mid-depth near the centre of the tank. For even small rotation rates, the measurements showed that the turbulent velocities were weakly affected by rotation at all depths, but as the rotation rate increased, the deviation from the non-rotational scaling slowly and progressively increased until eventually the turbulent velocities were fully rotationally controlled. The results indicated that there was no sudden transition of the turbulent field from the non-rotational state (a function only of the surface buoyancy flux B and the depth z) to the rotational state (where the strength of the turbulent field is a function of only B and the Coriolis parameter f). Rather the transition was a smooth asymptotic one from one state to the other. Nevertheless, it was possible to parametrize this transition by a single value of the turbulent or small scale Rossby number, defined by Ro = (B/f³z²)^1/3. Our measurements suggested a critical value of Ro_c ≈ 0.1, below which the turbulence was fully rotationally controlled and which was equivalent to a critical depth z_c = (35 ± 15)(B/f³)^1/2. Using typical oceanic values for B and f, the oceanic turbulence driven by surface cooling events becomes rotationally controlled only for depths greater than about 10 km, a depth which is greater than that of the bulk of the world's oceans. Thus, convective turbulence actively being generated by cooling of the ocean surface is best described by non-rotating turbulent velocity and length scales and is a function only of the surface buoyancy flux and the depth.  相似文献   

The Geochemical Effects of Microbial Humic Substances Reduction     

John D. Coates  Romy Chakraborty  Susan M. O&#x;Connor  Claudia Schmidt  Jürgen Thieme 《洁净——土壤、空气、水》2001,28(7):420-427

As part of a study on microbial redox alteration of humic substances we investigated the potential effect of this metabolism on the fate of heavy metals and hydrocarbons as a result of conformational alteration of the humic molecular structure due to microbial reduction. Our studies indicate that the microbial reduction of humic acids (HA) results in significant morphological and geochemical alterations. X‐ray microscopy analysis indicate that the conformational structure of the humic colloids is altered as a result of the redox change. In the reduced state, the HA appeared as small dense particles, on reoxidation, large loose aggregates were formed. In addition, spectrofluorometric studies indicated that the binding capacity of the HA for naphthalene was decreased by 10% when the HA was reduced. Similarly, the reduced HA yielded higher surface tension values at all concentrations tested which is indicative of a more hydrophilic and less hydrophobic solute. On reoxidation, the surface tension values reverted back to values similar to those obtained for the untreated oxidized HA. These data indicate that the hydrophobicity of the HA is altered on biological reduction of the HA and that this alteration is reversible. In contrast the reduced HA demonstrated a 15% higher affinity for heavy metals such as divalent cobalt than the oxidized HA. In addition to increasing the binding capacity of HA for heavy metals, the reduction of the HA also decreased the bioavailability and toxicity of bound heavy metals such as chromium. When incubated in the presence of Cr(III) and HA, cells of Escherichia coli grew much more rapidly in the presence of the reduced HA suggesting that the higher metal binding capacity of the reduced humic substances resulted in a removal of the Cr(III) from solution and hence reduced its bioavailability and toxicity. These studies demonstrate that HA redox state and reduction of humic acids by microorganisms can have a significant effect on the molecular morphology and binding constants of HA for heavy metals and hydrocarbons and also directly affects the bioavailability of these compounds in the environment.  相似文献   

AXIOM: advanced X-ray imaging of the magnetosphere   总被引：1，自引：0，他引：1  

Graziella Branduardi-Raymont  Steve F. Sembay  Jonathan P. Eastwood  David G. Sibeck  Tony A. Abbey  Patrick Brown  Jenny A. Carter  Chris M. Carr  Colin Forsyth  Dhiren Kataria  Steve Kemble  Steve E. Milan  Chris J. Owen  Lisa Peacocke  Andy M. Read  Andrew J. Coates  Michael R. Collier  Stan W. H. Cowley  Andrew N. Fazakerley  George W. Fraser  Geraint H. Jones  Rosine Lallement  Mark Lester  F. Scott Porter  Tim K. Yeoman 《Experimental Astronomy》2012,33(2-3):403-443

Planetary plasma and magnetic field environments can be studied in two complementary ways—by in situ measurements, or by remote sensing. While the former provide precise information about plasma behaviour, instabilities and dynamics on local scales, the latter offers the global view necessary to understand the overall interaction of the magnetospheric plasma with the solar wind. Some parts of the Earth’s magnetosphere have been remotely sensed, but the majority remains unexplored by this type of measurements. Here we propose a novel and more elegant approach employing remote X-ray imaging techniques, which are now possible thanks to the relatively recent discovery of solar wind charge exchange X-ray emissions in the vicinity of the Earth’s magnetosphere. In this article we describe how an appropriately designed and located X-ray telescope, supported by simultaneous in situ measurements of the solar wind, can be used to image the dayside magnetosphere, magnetosheath and bow shock, with a temporal and spatial resolution sufficient to address several key outstanding questions concerning how the solar wind interacts with the Earth’s magnetosphere on a global level. Global images of the dayside magnetospheric boundaries require vantage points well outside the magnetosphere. Our studies have led us to propose ‘AXIOM: Advanced X-ray Imaging of the Magnetosphere’, a concept mission using a Vega launcher with a LISA Pathfinder-type Propulsion Module to place the spacecraft in a Lissajous orbit around the Earth–Moon L1 point. The model payload consists of an X-ray Wide Field Imager, capable of both imaging and spectroscopy, and an in situ plasma and magnetic field measurement package. This package comprises a Proton-Alpha Sensor, designed to measure the bulk properties of the solar wind, an Ion Composition Analyser, to characterise the minor ion populations in the solar wind that cause charge exchange emission, and a Magnetometer, designed to measure the strength and direction of the solar wind magnetic field. We also show simulations that demonstrate how the proposed X-ray telescope design is capable of imaging the predicted emission from the dayside magnetosphere with the sensitivity and cadence required to achieve the science goals of the mission.  相似文献   

Carbon dioxide photoelectron energy peaks at Mars     

R.A. Frahm  J.D. Winningham  J.R. Scherrer  A.J. Coates  D.O. Kataria  S. Barabash  H. Andersson  A. Grigoriev  T. Säles  W. Schmidt  J.U. Kozyra  E.C. Roelof  S. Livi  K.C. Hsieh  M. Grande  J.-A. Sauvaud  J.-J. Thocaven  S. Orsini  M. Maggi  P. Bochsler  J. Woch  K. Asamura 《Icarus》2006,182(2):371-382

The ELectron Spectrometer (ELS) from the Analyzer of Space Plasmas and Energetic Atoms (ASPERA-3) flown on the Mars Express spacecraft has an 8% energy resolution, combined with the capability to oversample the martian electron distribution. This makes possible the resolution and identification of electrons generated as a result of the He 304 Å ionization of CO₂ at the martian exobase on the dayside of the planet. Ionospheric photoelectrons were observed during almost every pass into the ionosphere and CO₂ photoelectron peaks were identified near the terminator. Atmospherically generated CO₂ photoelectrons are also observed at 10,000 km altitude in the martian tail near the inner magnetospheric boundary. Observations over a wide range of spacecraft orbits showed a consistent presence of photoelectrons at locations along the inner magnetospheric boundary and in the ionosphere, from an altitude of 250 to 10,000 km.  相似文献   

A pre-shock event at Jupiter on 30 January 2001     

Karoly Szego  David T. Young  Bruce Barraclough  Andrew J. Coates  Michele K. Dougherty  Donald A. Gurnett  Andrea Opitz  Michelle F. Thomsen 《Planetary and Space Science》2006,54(2):200-211

In this paper we analyze a pre-shock event that we observed in the foot region of the quasi-parallel bow shock (BS) that the Cassini spacecraft crossed on 30 January 2001, at about 1030 UT. Before crossing the BS, the incoming solar wind first decelerated, and then the bulk velocity both of the proton and α components increased, the flow accelerated and decelerated, heated and cooled several times. We characterize the plasma in the foot using the data measured by the magnetometer, the radio and plasma wave science (RPWS) instrument, and the Cassini plasma spectrometer (CAPS) being carried onboard the Cassini spacecraft, and analyze the observations. We argue that the velocity and temperature changes can be caused by firehose instabilities excited by ions reflected from the shock. We investigate another possibility, shocklet formation, to account for the observed features, but conclude that this explanation seems to be less likely. In the foot we also identified both backstreaming electrons and ions and electrostatic waves in the 100-1000 Hz range very likely excited by the backstreaming electrons.  相似文献   

Electric fields within the martian magnetosphere and ion extraction: ASPERA-3 observations     

E. Dubinin  R. Lundin  J. Woch  A. Fedorov  N. Krupp  M. Holmström  M. Yamauchi  J.-J. Thocaven  J. Sharber  A. Coates  K.S. Hsieh  H. Koskinen  P. Riihelä  T. Säles  J. Luhmann  R. Cerulli-Irelli  M. Maggi  D. Williams  P. Wurz  C. Dierker  M. Carter 《Icarus》2006,182(2):337-342

Observations made by the ASPERA-3 experiment onboard the Mars Express spacecraft found within the martian magnetosphere beams of planetary ions. In the energy (E/q)-time spectrograms these beams are often displayed as dispersive-like, ascending or descending (whether the spacecraft moves away or approach the planet) structures. A linear dependence between energy gained by the beam ions and the altitude from the planet suggests their acceleration in the electric field. The values of the electric field evaluated from ion energization occur close to the typical values of the interplanetary motional electric field. This suggests an effective penetration of the solar wind electric field deep into the martian magnetosphere or generation of large fields within the magnetosphere. Two different classes of events are found. At the nominal solar wind conditions, a ‘penetration’ occurs near the terminator. At the extreme solar wind conditions, the boundary of the induced magnetosphere moves to a more dense upper atmosphere that leads to a strong scavenging of planetary ions from the dayside regions.  相似文献