Atmospheric circulation and storminess derived from Royal Navy logbooks: 1685 to 1750

This paper is concerned with the use of Royal Navy ships’ logbooks for the period 1685 to 1750, thereby embracing the oldest members of this documentary series that extends to the present day. The geographic range of the undertaking is confined to the English Channel and its western approaches where the abundance of logbooks for this period allows for the abstraction of a daily series of wind force and direction data. These are verified and processed for inclusion in a database from which indices are derived for air circulation patterns based on the frequency of winds from north, east, south and west quarters, and of gale frequency, based on the contemporary terminology of wind force. The methods by which the data are abstracted and processed are described, as is the nature of the raw data and source material. The results provide a uniquely detailed insight into the changing patterns of air circulation over this critical period that marked the transition from the depths of the Little Ice Age in the late seventeenth century. Attention is also drawn to the changing nature of gale frequency, which revealed a notable decrease over the study period. Associations between changing circulation patterns and temperature regimes are also explored.     

Cartography in the era of informatization: New problems and possibilities

This paper is concerned with some issues related to the changes in the role, properties and characteristics of cartography in connection with the transition of mankind from the industrial age to the information (post-industrial) age. Emphasis is placed on the essence of the process of perception of the environment by humans through data provided to them where the object of perception and the subject perceiving information are located at different points of the space-time continuum. The study identifies eight characteristic features of the information age, the new challenges and requirements, the possibilities of information society, and the related new tasks of cartographic support of the economy. It is shown that the main difference of the information age from the industrial age implies a transition from the commodity-producing economy to the economy of information services. Based on this, it is concluded that there is a need for the provision of various cartographic services, such as the generation of cartographic information as requested as well as supplying it to various users. Seven main statements are formulated, which characterize the peculiarities, properties and methodological foundations of cartography under the new conditions. The definitions of the role and subject of cartography in the information age are suggested. An interpretation is given to the term “neocartography”, and its main characteristics are presented. The notion of a multipurpose cartographic resource is introduced.     

Geomagnetic secular acceleration

Summary. A spherical harmonic model of the second time-derivative of the geomagnetic field is determined, for the first time, directly from measures of the secular acceleration based on observatory annual mean data. The data span the interval 1964.5–1975.5, and 165 observatories are included. The model comprises the 32 coefficients of degree and order up to 6 that are significant at the 5 per cent level. Its primary purpose is to aid in the reduction of data to epoch for the 1980 series of navigational charts. The model is compared with earlier estimates of secular acceleration, derived by less direct methods.     

HUMAN IMPACTS ON THE ENVIRONMENT: UNPREDICTABILITY AND THE PRIMACY OF PLACE

Landscapes, environments, and ecosystems (i.e., places) are historically and spatially contingent and therefore unique. Generalizations and laws are based on “all other things being equal.” Owing to historical and spatial contingency, all other things are never completely equal and often do not approach that ideal closely enough to allow for reliable prediction. The problem is illustrated by examining effects of grazing and fire suppression on transitions between grass and woody vegetation communities. In three different environments in the southern United States (central Texas, southwestern Virginia, and eastern North Carolina), three different relationships exist between grazing and fire regime, and vegetation. Other examples are common in the geographic and environmental literature. This suggests that the search for a single applicable generalization or predictive model of a given human-induced environmental change that can be applied without accounting for the particular characteristics of places may be futile. Several general ways to address this issue are suggested. First is the recognition that place matters. Conditions specific to a location or region will influence what, how, or even if generalizations apply. Second is the adoption of a “demographic” approach. This is based on the idea that for places, like people, it is possible to make aggregate or probabilistic generalizations or predictions, but these cannot be applied to deterministic prediction of individuals. Third is a synoptic approach based on forecasting not via simple cause-effect relationships, but based on a typology of situations that recognizes and incorporates the unique characteristics of site and situation. Several converging threads of inquiry in geography and geosciences explicitly or implicitly address the issue of historical and spatial contingency. [Key words: landscape, environment, place, prediction.]     

Stochastic model-based methods for handling uncertainty in areal interpolation

Handling of uncertainty in the estimation of values from source areas to target areas poses a challenge in areal interpolation research. Stochastic model-based methods offer a basis for incorporating such uncertainty, but to date they have not been widely adopted by the GIS community. In this article, we propose one use of such methods based in the problem of interpolating count data from a source set of zones (parishes) to a more widely used target zone geography (postcode sectors). The model developed also uses ancillary statistical count data for a third set of areas nested within both source and target zones. The interpolation procedure was implemented within a Bayesian statistical framework using Markov chain Monte Carlo methods, enabling us to take account of all sources of uncertainty included in the model. Distributions of estimated values at the target zone level are presented using both summary statistics and as individual realisations selected to illustrate the degree of uncertainty in the interpolation results. We aim to describe the use of such stochastic approaches in an accessible way and to highlight the need for quantifying estimation uncertainty arising in areal interpolation, especially given the implications arising when interpolated values are used in subsequent analyses of relationships.     

Crack nucleation in saturated porous media

Crack nucleation has been the subject of important contributions in the last two last decades. However, it seems that few attention has been granted to the case of saturated porous media. This is the question addressed in the present paper which is devoted to nucleation in traction mode. From a physical point of view, nucleation is a sudden phenomenon, so that the material response is both adiabatic and undrained. In the spirit of the variational approach, the nucleated crack is viewed as the final state of a region of space in which the material undergoes a full damage process. In traction mode, the opening of a saturated crack in undrained condition induces a drop of fluid pressure. In case of low fluid compressibility, the presence of the fluid delays the brittle failure usually associated with nucleation, as long as the fluid pressure remains above the saturation vapor pressure. Nucleation is therefore possible only if a partial vaporization of the fluid takes place.     

Fission tracks in minerals: Annealing kinetics,track structure and age correction

It is shown that the annealing kinetics of fission tracks in apatite can be described by a sum of exponential decay functions. From an analysis of the temperature dependence of this annealing law it is concluded that the etchability of fission tracks is due to extended defects, i.e. systems of dislocation loops. The multiexponential annealing law is also applied to prove that the plateau correction method is basically correct, but rather as a method for determining a lower limit than the “true” fission track age.