Changes in Surface and Subsurface Temperatures after Clearing Forest in Western Australia

Author(s):  
Makoto Taniguchi ◽  
David R. Williamson ◽  
Adrian J. Peck
2010 ◽  
Vol 50 (1) ◽  
pp. 411
Author(s):  
Ameed Ghori

The Geological Survey of Western Australia (GSWA) is providing new heat flow data and continuing studies in subsurface temperatures to understand the origin, migration and accumulation of geofluids in petroleum and geothermal systems of the Canning Basin. The study includes an investigation of subsurface temperatures from 274 wells, thermal conductivity measurement of 50 core samples from 22 wells, and single-dimensional (1D) heat-flow modelling of 101 wells. Thermal conductivity measurement of Canning Basin formations range from 1.06–5.83 W/mºC and modelled surface heat-flow ranges from 20–160 mW/m². The lowest measured thermal conductivity is in the Ordovician Goldwyer Formation at 1.06± 0.28 W/mºC, and the highest values are in the Upper Carboniferous Reeves Formation at 5.83 ± 0.22 W/mºC. Generally, estimated heat-flow values are lower where thick sedimentary deposits are present such as the Fitzroy Trough, Lennard Shelf, and Kidson Sub-basin, with values less than 65 mW/m². The heat flow values increase to over 80 mW/m² on the Broome Platform and Jurgurra, Mowla and Barbwire terraces. Lower heat-flow values have been modelled in West Blackstone–1 (47 mW/m²), Curringa–1 (52 mW/m²), Kennedia–1, Napier–2 and Pearl–1 (55–52 mW/m²). Higher heat-flow values have been modelled in Goodenia–1, Lovells Pocket–1, Kanak–1, Cudalgarra North–1, and Cudalgarra–1, where heat-flow values are over 100 mW/m². These new thermal conductivities, corrected temperatures, and heat-flow values support improved modelling of the Canning Basin petroleum and geothermal systems.


2020 ◽  
Vol 646 ◽  
pp. 79-92
Author(s):  
RE Scheibling ◽  
R Black

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.


2020 ◽  
Vol 11 (2) ◽  
pp. 188-203
Author(s):  
Roy Jones ◽  
Tod Jones

In the speech in which the phrase ‘land fit for heroes’ was coined, Lloyd George proclaimed ‘(l)et us make victory the motive power to link the old land up in such measure that it will be nearer the sunshine than ever before … it will lift those who have been living in the dark places to a plateau where they will get the rays of the sun’. This speech conflated the issues of the ‘debt of honour’ and the provision of land to those who had served. These ideals had ramifications throughout the British Empire. Here we proffer two Antipodean examples: the national Soldier Settlement Scheme in New Zealand and the Imperial Group Settlement of British migrants in Western Australia and, specifically, the fate and the legacy of a Group of Gaelic speaking Outer Hebrideans who relocated to a site which is now in the outer fringes of metropolitan Perth.


2008 ◽  
Vol 31 (3) ◽  
pp. 111-124 ◽  
Author(s):  
Margot Willing ◽  
Susan Stöcklmayer ◽  
Martin Wills
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