Hyperspectral image analysis of different carbonate lithologies (limestone,karst and hydrothermal dolomites): the Pozalagua Quarry case study (Cantabria,North‐west Spain)

Ground‐based hyperspectral imaging combined with terrestrial lidar scanning is a novel technique for outcrop analysis, which has been applied to Early and Late Albian carbonates of the Pozalagua Quarry (Cantabrian Mountains, Spain). An image processing workflow has been developed for differentiating limestone from dolomite, providing additional sedimentary and diagenetic information, and the possibility to quantitatively delineate diagenetic phases in an accurate way. Spectral absorption signatures can be linked to specific sedimentary or diagenetic products, such as recent and palaeokarst, hydrothermal karst, (solution enlarged) fractures and different dolomite types. Some of the spectral signatures are related to iron, manganese, organic matter, clay and/or water content. Ground‐truthing accessible parts of the quarry showed that the classification based on hyperspectral image interpretation was very accurate. This technique opens the possibility for quantitative data evaluation on sedimentary and diagenetic features in inaccessible outcrops. This study demonstrates the potential of ground‐based imaging spectroscopy to provide information about the chemical–mineralogical distribution in outcrops, which could otherwise not be established using conventional field methods.     

Effects of late Pleistocene permafrost on the landscape of Wisconsin, USA

Pleistocene permafrost had a major but generally unappreciated effect on the landscape of Wisconsin, second only to glaciation. Evidence for continuous permafrost during the last part of the Wisconsin Glaciation includes ice-wedge casts seen both in outcrop (generally in gravel pits) and as polygonal networks (on aerial photographs). Other important evidence includes fossil tundra organisms. Other features that are probably the result of permafrost in Wisconsin include talus cones, block streams, solifluction rubble at the base of most hillslopes, fluvial cobble gravel, gullies that are today inactive, lake-ice collapse trenches, and ice-walled-lake plains. Permafrost caused accelerated regional erosion of the landscape; most topographic features formed before the last permafrost melted have been highly modified or even destroyed, whereas those formed after are much better preserved. In addition, the presence of permafrost influenced many glacial processes and landforms. Permafrost was present until about 14000 yr BP in the southern part of the state to about 10000 yr BP in the northern part.     

Exceptionally long, narrow drumlins formed in subglacial cavities, North Dakota

An array of about 200 exceptionally long and narrow drumlins occurs in north-central North Dakota. The most prominent of the drumlins is 27 km long, and their average length is between 2 km and 3 km. The drumlin field is closely associated with, and occurs immediately up-glacier from, an extensive area of ice-thrust topography. Most of the drumlin ridges have small glacier-thrust masses at their heads. Internal structures are complex, but typically include large numbers of gravity faults, which dip away from the center of the drumlin ridges. Materials contained in the drumlins were transported from higher pressure areas beneath the glacier, inward toward lower pressure areas (cavities) by flowing, thrusting, squeezing and other processes. The close and systematic association of the long drumlins with nearby areas of ice-thrust topography indicates a genetic tie; conditions that caused the glacier to form large ice thrusts also contributed to drumlin formation. Major factors involved in the formation of the drumlins were high porewater pressures in interbedded permeable and impermeable materials beneath a thin, swiftly flowing glacier, and the presence of areas of frozen ground near the margin of the glacier.     

VARIANCE-DECOMPOSITION OF PURE-COMPONENT SPECTRA AS A MEASURE OF SELECTIVITY

Care is required for multicomponent analysis if misleading results are to be avoided. The problem ofill-conditioned calibration matrices is of primary concern. This type of numerical instability isrepresented as spectral overlap of calibration spectra. Depending on the degree of spectral overlap, thesample concentration estimates can be severely affected. A practical statistical procedure is discussedwhich tests for the presence of spectral overlap among the pure-component spectra and simultaneouslyassesses the degree that concentration estimates may be degraded. Guidelines are developed to ascertainhow much departure from spectral orthogonality is acceptable.     

TESTING FOR REDUNDANCY IN PRODUCT QUALITY CONTROL TEST CRITERIA:AN APPLICATION TO AVIATION TURBINE FUEL

Given a set of test criteria that determine a quality specification,the question often arises whether anyof the tests are redundant because of intercorrelations.Simple selection of tests on the basis of partialcorrelations with the other tests is rejected on the basis that the random error in the data may be causingspurious correlations.One method is to use cross-validation to define the systematic principal components and examine thecorrelation structure in this reduced space.It is shown that the presence of principal componentsdominated by individual tests(‘variable specific’PCs),which are indicated by cross-validation as beingnon-systematic,must be taken into account.Having defined the dimensionality,a variable reductionmethod based on Procrustes rotation selects subsets of tests that preserve the structure of the samples inmultivariate space.This is an attractive proposition in the context of maintaining a quality controlspecification.It is also shown that the variable reduction technique can be used to aid the identificationof the true dimensionality of the data space.This approach is applied to a number of routine tests carriedout on aviation turbine fuel.     

Coastal dune conservation on an Irish commonage: community-based management or tragedy of the commons?

In Ireland 'commonage' refers to lands jointly owned by several individuals who have grazing rights. Commonage can provide the low-intensity grazing regime regarded as optimal for habitat conservation, and it is also unlikely to suffer the negative impacts of building development or coastal engineering. Today, however, the traditional control systems of coastal commonage are generally moribund, leading to habitat degradation. The only viable future management model is likely to be one based on local community control. Community management would have the legitimacy to counter the negative perceptions of external authority that generate environmental degradation.     

Regulation of sand transport in the Colorado River by changes in the surface grain size of eddy sandbars over multi-year timescales

In settings where the transport of sand is partially or fully supply limited, changes in the upstream supply of sand are coupled to changes in the grain size of sand on the bed. In this manner, the transport of sand under the supply-limited case is ‘grain-size regulated’. Since the closure of Glen Canyon Dam in 1963, the downstream reach of the Colorado River in Marble and Grand Canyons has exhibited evidence of sand-supply limitation. Sand transport in the river is now approximately equally regulated by changes in the discharge of water and changes in the grain sizes of sand on the channel bed and eddy sandbars. Previous work has shown that changes in the grain size of sand on the bed of the channel (driven by changes in the upstream supply of sand owing to both tributary floods and high dam releases) are important in regulating sand transport over timescales of days to months. In this study, suspended-sand data are analysed in conjunction with bed grain-size data to determine whether changes in the grain size of sand on the bed of the channel or changes in the grain size of sand on the surface of eddy sandbars have been more important in regulating sand transport in the post-dam Colorado River over longer, multi-year timescales. The results of this study show that this combined theory- and field-based approach can be used to deduce which environments in a complicated setting are the most important environments for regulating sediment transport. In the case of the regulated Colorado River in Marble and Upper Grand Canyons, suspended-sand transport has been regulated mostly by changes in the surface grain size of eddy sandbars.     

UTOPIA,DYSTOPIA, AND SUBLIME APOCALYPSE IN MONTANA'S CHURCH UNIVERSAL AND TRIUMPHANT

ABSTRACT. The search for a perfected place on earth is rarely easy or forgiving. Utopias and dystopias demonstrate the practical frailties of attempts to build better human associations, whether as literary efforts or in actual, on‐the‐ground experiments. With a proprietary interest in evaluating the dimensions of place making, geographers can lay claim to be frontline critics of efforts that attempt to craft a better world. The catalog of personality cultists, charismatically murderous leaders, and apocalyptic mass death is long. The Church Universal and Triumphant, currently of Paradise Valley, Montana, is examined as the home for twenty‐five years of an ongoing effort to “improve” lives. If its dilemmas and apparent failures are in keeping with the history of past utopian ventures, geographical lessons remain to be learned about the costs of planning for perfection.