Reviews

GEOMORPHOLOGY by R. J. Chorley, S. A. Schumm and D. E. Sugden.’ 19 × 25 cm, xxiii and 605 pages. Methuen: London 1984 (ISBN 0 416 32590 4) $A39.95 (cloth).

THEMES IN GEOMORPHOLOGY edited by A. F. Pitty. 13 × 21 cm, 280 pages. Croom Helm: London 1985 (ISBN 0 7099 2066 0) $A49.50 (cloth).

DESERTS AND ARID LANDS edited by F. El‐Baz. 16 × 25 cm, vi and 222 pages. Nijhoff: The Hague 1984 (ISBN 90 247 2850 9) $US46.00 (cloth).

COASTAL GEOMORPHOLOGY IN AUSTRALIA edited by B. G. Thorn. 16 × 24 cm, xv and 349 pages. Academic Press: Sydney 1984 (ISBN 0 12 687880 3) $A49.50 (cloth).

KWONGAN: Plant Life on the Sandplain edited by J. S. Pate and J. S. Beard. University of Western Australia Press: Nedlands 1984 (ISBN 0 85564 230 0) $A25.00 (limp).

THEMES IN BIOGEOGRAPHY edited by J. A. Taylor. 22 × 14 cm, xxvii and 404 pages. Croom Helm: London 1984 (ISBN 0 7099 2428 3) $A25.95 (limp).

ENVIRONMENTAL IMPACT ASSESSMENT: A Practical Guide by C. F. Porter. 22 × 15 cm, xiii and 269 pages. University of Queensland Press: St Lucia 1985 (ISBN 0 7022 1699 2) $A35.00 (cloth).

THE CLIMATIC SCENE edited by M. J. Tooley and G. M. Sheail. 16 × 24 cm, xx and 306 pages. George Allen and Unwin: London 1985 (ISBN 0 04 551089 X) $A59.95 (cloth).

VOLCANIC HAZARDS: A Sourcebook on the Effects of Eruptions by R. J. Blong. 24 × 15 cm, xvi and 424 pages. Academic Press: Sydney 1984 (ISBN 0 12 107180 4) $A68.00 (cloth).

THE ECONOMICS OF BUSHFIRES: The South Australian Experience edited by D. T. Healey, F. G. Jarrett and J. M. McKay. 22 × 15 cm, x and 152 pages. Oxford University Press: Melbourne 1985 (ISBN 0 19 554669 5) $A19.99 (cloth).     

Hydrochemical and sedimentary responses of paired High Arctic watersheds to unusual climate and permafrost disturbance,Cape Bounty,Melville Island,Canada

High Arctic river responses to changing hydroclimatic and landscape processes are poorly understood. In non‐glacierized basins, snowmelt and rainfall generate river discharge, which provides first order control over fluxes. Further factors include the seasonality of precipitation, seasonal active layer development, and permafrost disturbance. These controls were evaluated in terms of sedimentary and biogeochemical fluxes from paired catchments at Cape Bounty, Melville Island, Nunavut during 2006–2009. Results indicate that the source of runoff can be more important than the amount of runoff for sediment, solutes, and organic yields. Although the snowmelt period is typically the most important time for these yields, heavy late summer precipitation events can create disproportionately large yields. Rainfall increases yields because it hydrologically connects areas otherwise isolated. Inorganic solute yields from late summer rainfall are higher because the thick active layer maximizes hydrologic interactions with mineral soils and generates high solute concentrations. Results also indicate that while the catchments are broadly similar, subtle topographic differences result in important inter‐catchment differences in runoff and suspended and dissolved loads. The East watershed, which had less extensive permafrost disturbance, consistently had higher concentrations of dissolved solids. These higher dissolved fluxes cannot therefore be explained by thermokarst features, but rather by deeper active layer development, due to a greater proportion of south‐facing slopes. Although warm temperatures in 2007 led to extensive active layer disturbance in the West watershed, because the disturbances were largely hydrologically disconnected, the total disturbed area was small, and inter‐annual variability in discharge was high, there was no detectable response in dissolved loads to disturbances. Sediment availability increased after 2007, but yields have largely returned to pre‐disturbance levels. Results indicate that seasonality and frequency‐magnitude characteristics of projected increases in precipitation must be considered along with active layer changes to predict the fluvial sedimentary and biogeochemical response to regional climate change. Copyright © 2011 John Wiley & Sons, Ltd.     

Improvements to Griggs-type apparatus for mechanical testing at high pressures and temperatures

New and improved techniques and apparatus for testing the mechanical properties of materials at high presures and temperatures are described. These include an improved Griggs-type deformation apparatus designed to operate to 5 GPa and associated servo-controlled hydraulic drive and electronics, the design of hydrostatic (molten alkali halide mixtures) pressure assemblies to measure flow stresses as low as a few MPa, the characterization of temperature gradients and friction in such assemblies, measurement of the melting curve of an alkali halide mixture used as a confining pressure medium, and the measurement of acoustic emissions.     

The movement of sediment in rivers

Sediment movement in rivers is a complex phenomenon. The rate of sediment transport is related to many variables such as water discharge, average flow velocity, stream power, energy slope, shear stress, water depth, particle size, water temperature, and strength of turbulence. Different theories of sediment transport were developed by assuming different independent variables as the dominant variables. This survey provides a comprehensive review of the important theories of incipient motion and sediment transport. It discusses basic concepts and findings upon which knowledge of sediment transport is based and presents mathematical derivations and equations only in sufficient detail to illustrate some basic concepts. Data collected from natural rivers and laboratory flumes are used to compare the accuracy and applicability of different sediment transport equations. Finally, procedures are suggested for selecting sediment transport equations under different flow and sediment conditions.     

The exchange coefficients for latent and sensible heat flux over lakes: Dependence upon atmospheric stability

Components of the energy budget of a small lake were estimated over the autumnal cooling period. Measured values of the stored thermal energy and radiative heating were used to evaluate several bulk formulae for sensible and latent heat transfer. Over 50–100 day intervals, bulk formulae for latent and sensible heat flux without stability corrections were as good as formulae that incorporated such corrections; both satisfactorily reproduced the measured heat storage data. Over shorter (daily to weekly) time-scales, predictions incorporating stability corrections were superior to those without stability corrections. Over daily periods when the atmosphere was nearly neutral or was unstable, a formulation for sensible and latent heat transfer designed for small-scale systems (cooling ponds and reservoirs) agreed closely with the usual large-scale (oceanic) bulk formulations. The corrections for stability in the small-scale formulation are based on laboratory and theoretical studies of free convection; the stability correction in the large-scale formulation uses a bulk Richardson number in a manner consistent with flux-profile theory. Both agreed with the measured data for the unstable and near-neutral cases. Under stable atmospheric conditions (in a daily average sense), both formulations underestimated the measured fluxes     

The last interglacial ocean

The final effort of the CLIMAP project was a study of the last interglaciation, a time of minimum ice volume some 122,000 yr ago coincident with the Substage 5e oxygen isotopic minimum. Based on detailed oxygen isotope analyses and biotic census counts in 52 cores across the world ocean, last interglacial sea-surface temperatures (SST) were compared with those today. There are small SST departures in the mid-latitude North Atlantic (warmer) and the Gulf of Mexico (cooler). The eastern boundary currents of the South Atlantic and Pacific oceans are marked by large SST anomalies in individual cores, but their interpretations are precluded by no-analog problems and by discordancies among estimates from different biotic groups. In general, the last interglacial ocean was not significantly different from the modern ocean. The relative sequencing of ice decay versus oceanic warming on the Stage 6/5 oxygen isotopic transition and of ice growth versus oceanic cooling on the Stage 5e/5d transition was also studied. In most of the Southern Hemisphere, the oceanic response marked by the biotic census counts preceded (led) the global ice-volume response marked by the oxygen-isotope signal by several thousand years. The reverse pattern is evident in the North Atlantic Ocean and the Gulf of Mexico, where the oceanic response lagged that of global ice volume by several thousand years. As a result, the very warm temperatures associated with the last interglaciation were regionally diachronous by several thousand years. These regional lead-lag relationships agree with those observed on other transitions and in long-term phase relationships; they cannot be explained simply as artifacts of bioturbational translations of the original signals.