Knowledge-based systems and geological survey

This personal and pragmatic review of the philosophy underpinning methods of geological surveying suggests that important influences of information technology have yet to make their impact. Early approaches took existing systems as metaphors, retaining the separation of maps, map explanations and information archives, organised around map sheets of fixed boundaries, scale and content. But system design should look ahead: a computer-based knowledge system for the same purpose can be built around hierarchies of spatial objects and their relationships, with maps as one means of visualisation, and information types linked as hypermedia and integrated in mark-up languages. The system framework and ontology, derived from the general geoscience model, could support consistent representation of the underlying concepts and maintain reference information on object classes and their behaviour. Models of processes and historical configurations could clarify the reasoning at any level of object detail and introduce new concepts such as complex systems. The up-to-date interpretation might centre on spatial models, constructed with explicit geological reasoning and evaluation of uncertainties. Assuming (at a future time) full computer support, the field survey results could be collected in real time as a multimedia stream, hyperlinked to and interacting with the other parts of the system as appropriate. Throughout, the knowledge is seen as human knowledge, with interactive computer support for recording and storing the information and processing it by such means as interpolating, correlating, browsing, selecting, retrieving, manipulating, calculating, analysing, generalising, filtering, visualising and delivering the results. Responsibilities may have to be reconsidered for various aspects of the system, such as: field surveying; spatial models and interpretation; geological processes, past configurations and reasoning; standard setting, system framework and ontology maintenance; training; storage, preservation, and dissemination of digital records

Commentary on a British Geological Survey Computing Archive (1965-85)

An account of the emergence of computer methods in geology, as a background to a restricted archive of documents which chronicle their application in the British Geological Survey

Geoscience after IT: Part F. Familiarization with quantitative analysis

Numbers, measurement and calculation extend our view of the world. Statistical methods describe the properties of sets of quantitative data, and can test models (particularly the model that observed relationships arose by chance) and help us to draw conclusions. Links between spatial and quantitative methods, through coordinate geometry and matrix algebra, lead to graphical representations for visualizing and exploring relationships. Multivariate statistics tie into visualization to look at pattern among many properties

Geological reasoning and the solid Earth systems model

Geological maps record conclusions from an interpretation based on observations, guided by (and testing) an understanding (important in its own right) of the likely evolution of historical configurations of systems of multi-resolution objects, processes and events in the solid Earth. Techniques based on digital mapping have led to more flexible presentations and to three-dimensional spatial models. We suggest that the techniques could be augmented and structured to assist geological survey organisations in recording the reasoning behind the interpretation – creating and maintaining an interoperable component of a more comprehensive model of solid Earth systems, with maps seen as illustrative visualisations rather than the end-product

Magnetic, orbital and charge ordering in the electron-doped manganites

The three dimensional perovskite manganites in the range of hole-doping $x > 0.5$ are studied in detail using a double exchange model with degenerate $e_g$ orbitals including intra- and inter-orbital correlations and near-neighbour Coulomb repulsion. We show that such a model captures the observed phase diagram and orbital-ordering in the intermediate to large band-width regime. It is argued that the Jahn-Teller effect, considered to be crucial for the region $x<0.5$, does not play a major role in this region, particularly for systems with moderate to large band-width. The anisotropic hopping across the degenerate $e_g$ orbitals are crucial in understanding the ground state phases of this region, an observation emphasized earlier by Brink and Khomskii. Based on calculations using a realistic limit of finite Hund's coupling, we show that the inclusion of interactions stabilizes th e C-phase, the antiferromagnetic metallic A-phase moves closer to $x=0.5$ while th e ferromagnetic phase shrinks in agreement with recent observations. The charge ordering close to $x=0.5$ and the effect of reduction of band-width are also outlined. The effect of disorder and the possibility of inhomogeneous mixture of competing states have been discussed.Comment: 42 pages, 16 figure

The case for transforming the geological survey knowledge system: where digital geoscience spatial models meet the semantic grid

As the Internet develops into a more powerful cyberinfrastructure (the Grid), Geological Survey knowledge will enter a framework where users assess its value by its relevance and evaluated reliability rather than its source, and artificial boundaries of place and discipline lose significance. Within Geological Surveys, much effort has been devoted to the development of the geological map through digital cartography. Consequently, a firm base already exists for more radical change to the geoscience knowledge system. The geoscience map is prepared from field records and structured data, and given meaning through the illustrated text narratives of map explanations. A more comprehensive view of this knowledge system is needed to gain the full benefits of the Grid. The flexibility of markup languages can link narrative to database, spatial modeling and semantic representations, and thereby combine the insights of human understanding with the power of computation. Rationalizing and extending the scope of existing ontologies (specifications of conceptualizations) to align their structure and vocabularies could provide a more comprehensive conceptual view. Thus, a major challenge for Geological Surveys will be to transform their knowledge system to conform to a new service-oriented infrastructure devised by others and its future evolution determined by users

The case for computer-based spatial models in geology : a progress report on Project 22A

Spatial modelling is a new name for an old concept. It refers to what has long been a core activity of a geological survey, namely, piecing together a picture of the geometrical configuration and disposition of sequences of strata or other rocks, their constituent materials, characteristics, and properties, and relating that picture to ideas of their history and origin. The novelty lies in basing the model on computer methods rather than the conventional reports, maps and cross-sections. This is not to suggest that the interpretation and ideas can come from anywhere other than the geologist. But it is suggested that a computer model could give a better medium for the geologist to express his ideas; build up his interpretations; organise, analyse, summarize and share his observational data; explore the consequences of his hypotheses; reconcile information from diverse sources with his expectations and background knowledge; display the results of his work and transmit them to the users

Suggestions for information architecture in systems geology

Some tentative suggestions about the information architecture of systems geology, that is, the form of representation, evaluation and evolution of the information and its integration as an orderly, coherent structure that enables it to work for its designed purpose and to meet user needs

Geoscience after IT: Index

Index to articles in Geoscience after I

Geoscience after IT: Part A. Defining Information Technology, its significance in geoscience, and the aims of this publication

Information technology deals with tools for handling information, notably computers and networks. It brings benefits such as more efficient and rigorous formulation and expression of ideas, and wider sharing and integration of knowledge. This review should help practicing geoscientists and students to gain a broader understanding of these changes and form a view on future trends