Ageing research in Australia: reflecting on Graeme Hugo’s four decades of contribution

ABSTRACT

Globally, population ageing is one of the most pressing social and policy issues faced today. Over the next two decades, Australian society will face dramatic increases in the proportion of the population aged 65 years and over, as the baby boomers move into older age and fertility levels remain low. Yet population ageing is not a surprising or new trend—demographic changes in the age profile of a population tend to occur incrementally rather than suddenly. As a demographer and geographer, Graeme Hugo drew attention to this trend in Australia’s population more than three decades ago. Throughout Graeme Hugo’s vast breadth of work over the past 40 years, there has been a consistent thread of demographic analysis and academic thought associated with the ageing of Australia’s population. This paper focuses on Hugo’s contributions to academic thought and policy on Australia’s ageing population and the challenges associated with this for both service delivery and health policy as Australian society moves into an unprecedented era of population ageing.     

Stability of massive ground ice bodies in University Valley,McMurdo Dry Valleys of Antarctica: Using stable O–H isotope as tracers of sublimation in hyper-arid regions

To date, studies of the stability of subsurface ice in the McMurdo Dry Valleys of Antarctica have been mainly based on climate-based vapor diffusion models. In University Valley (1800 m), a small glacier is found at the base of the head of the valley, and adjacent to the glacier, a buried body of massive ice was uncovered beneath 20–40 cm of loose cryotic sediments and sandstone boulders. This study assesses the origin and stability of the buried body of massive ice by measuring the geochemistry and stable O–H isotope composition of the ice and applies a sublimation and molecular diffusion model that accounts for the observed trends. The results indicate that the buried massive ice body represents an extension of the adjacent glacier that was buried by a rock avalanche during a cold climate period. The contrasting δ¹⁸O profiles and regression slope values between the uppermost 6 cm of the buried massive ice (upward convex δ¹⁸O profile and S_D-18O = 5.1) and that below it (progressive increase in δ¹⁸O and S_D-18O = 6.4) suggest independent post-depositional processes affected the isotope composition of the ice. The upward convex δ¹⁸O profile in the uppermost 6 cm is consistent with the ice undergoing sublimation. Using a sublimation and molecular diffusion model, and assuming that diffusion occurred through solid ice, the sublimation rate needed to fit the measured δ¹⁸O profile is 0.2 ? 10^? 3 mm yr^? 1, a value that is more similar to net ice removal rates derived from ³He data from cobbles in Beacon Valley till (7.0 ? 10^? 3 mm yr^? 1) than sublimation rates computed based on current climate (0.1–0.2 mm yr^?1). We suggest that the climate-based sublimation rates are offset due to potential ice recharge mechanisms or to missing parameters, particularly the nature and thermo-physical properties of the overlying sediments (i.e., temperature, humidity, pore structure and ice content, grain size).     

Analysis of multiple enteric viral targets as sewage markers in coral reefs

Water and coral mucus samples were collected from throughout the Florida Keys National Marine Sanctuary and the Dry Tortugas for three years and were analyzed for human enteric viruses (enteroviruses, noroviruses, hepatitis A virus and adenoviruses) as conservative markers of human sewage using molecular methods. Of the 100 coral and water samples collected, 40 contained genetic material from one or more human enteric viruses. DNA-based adenoviruses were detected widely, in 37.8% of samples and at 91% of stations, including ‘pristine’ reefs in the Dry Tortugas; however, the detection rate was 12% for the RNA-based enteroviruses and noroviruses (hepatitis A virus was never detected). The disparity between the prevalence of RNA- and DNA-based viruses suggests the need for additional work to determine the utility of adenovirus as marker of human sewage.     

GEOGRAPHICAL INFORMATION SYSTEMS AND PHOTOGRAMMETRY ORGANISATIONAL ISSUES

This paper was presented at the 1990 Thompson Symposium. It distinguishes between geographical information systems (GIS) as a set of hardware and software tools and the institutional problems that arise when implementing GIS in an organisational environment. It examines issues such as data quality, that arise when treating information as a corporate resource, as well as the legal, economic and social constraints on the use of data.     

Interaction between local tectonics and glacial unloading on the Pacific margin of Canada

Variations in Late Quaternary coastal deformation along the Pacific margin of Canada reflect not only differences in glacial history, but also local non-glacial tectonics. A forebulge developed to the north in the Queen Charlotte Basin (QCB) from 13.2 until after 9.7 ka BP resulting in exposure of the currently submerged shelf; whereas similar exposure was not evident to the south in the Georgia Basin. A semi-quantitative effective elastic lithosphere thickness of between 10 and 20 km is estimated for the QCB. We propose that this warm, relatively thin lithosphere combined with tectonic movement influenced crustal displacement, particularly the decoupling of the North American plate along the Queen Charlotte (QC) Fault, which may have allowed the QCB to behave like a hinge in response to glacial unloading. This would explain large magnitude crustal tilting (2.1 m km⁻¹) observed adjacent to the QC Fault. The 50 m of depression observed in the early- and mid-Holocene may imply that the western edge of the North America Plate ‘flexed’ down below present elevation, producing a second wave of response to ice loading and unloading.     

Electrical Resistivity Studies to Delimit Zones of Acceptable Ground Water Quality

A total of four vertical electrical soundings were conducted in a layered andesitic rock aquifer known in places to yield ground water with total dissolved solids (TDS) in excess of 2,000 milligrams per liter (mg/L). The objective of the soundings was to locate zones of moderate to high permeability but with acceptable chemical quality.
The resistivity of a geologic unit is a function that includes the quantity of total dissolved solids in the interstitial water and the distribution of the water within the unit. Thus, the resistivity of most granular soils and rocks is controlled more by porosity, water content and water quality than by the conductivity of the matrix materials.
The electrical data delimited a drill site where it was believed that ground water of acceptable chemical quality could be expected. Completion and test pumping of two exploration wells confirmed the electrical sounding results.
The first test well drilled prior to the survey yielded only small amounts of ground water with total dissolved solids in excess of 2,000 mg/L. The second exploration well drilled at the site as a result of the electrical study yielded in excess of 100 gallons per minute of ground water with total dissolved solids of 830 mg/L.     

The 2004 RAS National Astronomy Meeting

This year's RAS National Astronomy Meeting was held at the Open University's Milton Keynes campus from 29 March to 2 April. The event was organized by members of the OU Physics & Astronomy Department and Planetary & Space Science Research Institute. Around 450 people attended the meeting, at which more than 220 talks were presented, along with around 90 posters. Co-chairs of RAS NAM04, Barrie Jones and Andrew Norton , summarize.