Ice-stream initiation, duration and thinning on James Ross Island, northern Antarctic Peninsula

Predicting the future response of the Antarctic Ice Sheet to climate change requires an understanding of the ice streams that dominate its dynamics. Here we use cosmogenic isotope exposure-age dating (26Al, 10Be and 36Cl) of erratic boulders on ice-free land on James Ross Island, north-eastern Antarctic Peninsula, to define the evolution of Last Glacial Maximum (LGM) ice in the adjacent Prince Gustav Channel. These data include ice-sheet extent, thickness and dynamical behaviour. Prior to ∼18 ka, the LGM Antarctic Peninsula Ice Sheet extended to the continental shelf-edge and transported erratic boulders onto high-elevation mesas on James Ross Island. After ∼18 ka there was a period of rapid ice-sheet surface-lowering, coincident with the initiation of the Prince Gustav Ice Stream. This timing coincided with rapid increases in atmospheric temperature and eustatic sea-level rise around the Antarctic Peninsula. Collectively, these data provide evidence for a transition from a thick, cold-based LGM Antarctic Peninsula Ice Sheet to a thinner, partially warm-based ice sheet during deglaciation.

Landscape evolution and ice-sheet behaviour in a semi-arid polar environment: James Ross Island, NE Antarctic Peninsula

This study of landscape evolution presents both new modern and palaeo process-landform data, and analyses the behaviour of the Antarctic Peninsula Ice Sheet through the Last Glacial Maximum (LGM), the Holocene and to the present day. Six sediment-landform assemblages are described and interpreted for Ulu Peninsula, James Ross Island, NE Antarctic Peninsula: (1) the Glacier Ice and Snow Assemblage; (2) the Glacigenic Assemblage, which relates to LGM sediments and comprises both erratic-poor and erratic-rich drift, deposited by cold-based and wet-based ice and ice streams respectively; (3) the Boulder Train Assemblage, deposited during a Mid-Holocene glacier readvance; (4) the Ice-cored Moraine Assemblage, found in front of small cirque glaciers; (5) the Paraglacial Assemblage including scree, pebble-boulder lags, and littoral and fluvial processes; and (6) the Periglacial Assemblage including rock glaciers, protalus ramparts, blockfields, solifluction lobes and extensive patterned ground. The interplay between glacial, paraglacial and periglacial processes in this semi-arid polar environment is important in understanding polygenetic landforms. Crucially, cold-based ice was capable of sediment and landform genesis and modification. This landsystem model can aid the interpretation of past environments, but also provides new data to aid the reconstruction of the last ice sheet to overrun James Ross Island.

Late-Holocene changes in character and behaviour of land-terminating glaciers on James Ross Island, Antarctica

Virtually no information is available on the response of land-terminating Antarctic Peninsula glaciers to climate change on a centennial timescale. This paper analyses the topography, geomorphology and sedimentology of prominent moraines on James Ross Island, Antarctica, to determine geometric changes and to interpret glacier behaviour. The moraines are very likely due to a late-Holocene phase of advance and featured (1) shearing and thrusting within the snout, (2) shearing and deformation of basal sediment, (3) more supraglacial debris than at present and (4) short distances of sediment transport. Retreat of ∼100 m and thinning of 15–20 m has produced a loss of 0.1 km3 of ice. The pattern of surface lowering is asymmetric. These geometrical changes are suggested most simply to be due to a net negative mass balance caused by a drier climate. Comparisons of the moraines with the current glaciological surface structure of the glaciers permits speculation of a transition from a polythermal to a cold-based thermal regime. Small land-terminating glaciers in the northern Antarctic Peninsula region could be cooling despite a warming climate.

Book reviews : David Palmer, Ross Shanahan, and Martin Shanahan, eds., Australian Labor history reconsidered

An objective of this collection is to bring the history of the Australian labor movement to international attention. The editors introduce the collection with a brief overview of Australian labor history, emphasizing differences between the Australian and American experiences. The introduction argues that a unique aspect of Australian labor history is “laborism,” which is defined as the central place of the labor movement in Australian culture, as compared with the more marginal position of the labor movement in America. In Australia, this centrality is reflected in the embedding of trade unions and labor in the state through wage-fixing tribunals, a social security system designed to support the families of male wage earners, and the Australian Labor Party's strong links to the trade union movement. The introduction is informative and especially benefits from the insights of David Palmer, an American historian teaching at Adelaide's Flinders University. However, the introduction was apparently written later at the suggestion of an American reader and has thus not been fully integrated into the structure of the book.

Polster and Ross " Maths Masters" articles

Burkard Polster and Marty Ross's 'Maths Masters' articles (previously reviewed in Vinculum) now linked with the 'Education Supplement' in The Age online are recommended to readers. Polster and Ross will be sending out e-mail alerts with a short summary of the latest article plus a link to where it is sitting on The Age online. E-mail alerts can be requested via Polster and Ross's website mathsmasters@qedcat.com

Reliability of a gymnastics vaulting feedback system

The current study assessed the intra- and inter-day reliability of a custom-built gymnastics vaulting feedback system. The system is a coach-friendly customized infra-red timing gate and contact timing mat system operated by the coach to augment the feedback provided to gymnasts on their vaulting performance during regular training practice. Thirteen Australian high performance gymnasts (eight males and five females) aged 11-23 years were assessed during two training sessions (Day 1 and Day 2) at their regular training centre. The approach velocity and board contact time measures were found to be reliable measures during vault training, with measures of pre-flight and table contact time less consistent. Future research should examine the validity of these measures as a tool for monitoring vault training.

The human nexus – a practical framework for inspiring trust and making ethical decisions

This overview of David Hume’s wide-ranging observations is a matrix portraying the key elements of a pragmatic pathway to a moral decision that can be applied in any situation where organisational decisions need to be made. 

Teaching ethics in organisational behaviour : a Humean viewpoint

Problem Statement: Concepts of ethics have rarely been easy to teach in the organizational behaviour curriculum. The philosophical bases of ethics are often abstract and prone to multiple interpretations and dilemmas. The changing global environment of organisations adds complexity to the interacting values that people bring into the workplace. To redress the situation, this articlerepresents the stance of David Hume on human morality and proposes an original nexus of his concepts for application in the teaching and learning of ethics in the field of organizational behaviour.

Method: Based on the literature, we develop a conceptual model from a thread drawn between Hume’s influence on the Scottish Enlightenment and accordingly the current complex business environment which was fostered in part by the economic models espoused by his Enlightenment associates. The concepts are presented as a matrix and relevant examples are explained in this context.

Results: Pointing out the challenge of the global rifts in organisational morality, we relate the fable of the traveller from Hume’s writings and make the point that the Humean nexus, now distilled from the elaborate reasoning of Hume, provides educators and managers alike with a helpful centre of gravity around which to develop analyses of decisions and actions in order to gain moral perspective that transcends time and place.

Conclusions: Business ethics lessons have sometimes been abstract and emotive in organisational Behavior education but the empirical concepts of Hume in this new form have the potential to be useful and agreeable for many.