Modelling uncertainty in natural resource analysis using fuzzy sets and Monte Carlo simulation: slope stability prediction

The techniques of fuzzy logic and Monte Carlo simulation are combined to address two incompatible types of uncertainty present in most natural resource data: thematic classification uncertainty and variance in unclassified continuously distributed data. The resultant model of uncertainty is applied to an infinite slope stability model using data from Louise Island, British Columbia. Results are summarized so as to answer forestry decision support queries. The proposed model of uncertainty in resource data analysis is found to have utility in combining different types of uncertainty, and efficiently utilizing available metadata. Integration of uncertainty data models with visualization tools is considered a necessary prerequisite to effective implementation in decision support systems.     

Expanding spread profile at the northern Jan Mayen Ridge

An expanding spread seismic profile at the central northern Jan Mayen Ridge, ESP-5, has yielded a crustal seismic velocity distribution which is similar to observations from the thinned continental crust at the Norwegian continental margin. The profile reveals a post-early Eocene sedimentary sequence, about 1. 5 km thick, overlying 1 km of volcanic extrusives and interbedded sediments. Below, there are about 3 km of pre-opening sediments above the seismic basement. The results indicate that the main ridge block is underlain by a thinned crust, possibly only 13.5 km thick. The results are compatible with a continental nature for the main ridge complex.     

The geography of elderly minority populations in the United States

A tremendous amount of attention has been given to the aging of population that is occurring in many parts of the world. However, very little work has focused upon the aging of minority populations. Because minority populations often have greater needs for health care and fewer resources to pay for it, it is important to assess the demand for services. This paper takes an initial step in that direction by focusing upon the geographic distribution of elderly minority populations in the United States. The study is carried out at several spatial scales, and it is concluded that elderly minority populations tend to be even more segregated than their non-elderly counterparts.     

THE AMERICAN CHALLENGE TO BRITISH HEGEMONY, 1861–1947*

ABSTRACT. In The Shaping of America Donald Meinig describes a United States averse to challenging Britain geostrategically but emerging as a powerhouse economy by the late 1890s. But America embarked on a sustained economic struggle with Britain in 1861 by embracing protectionism; America's Civil War ironclads were as much to resist Britain as fight the Confederacy; and in 1866 uss Miantonomoh helped persuade Britain to reconsider, then pay, the Alabama Claims. Britain never retaliated in the economic struggle by moving to protectionism and in the late 1800s began to appease America in geostrategic terms. This struggle intensified in the 1920s and 1930s as America and Britain competed for control of international transportation, international communication, and the global oil supply, but by the mid‐1940s American hegemony was clear. This article traces the course of the complex economic and political struggle for hegemony in the light of recent models of transitions in the world economy.     

Involutions in the Middle Pleistocene (Anglian) Barham Soil, eastern England: a comparison with thermokarst involutions from arctic Canada

Involutions in the early Anglian Barham Soil at Newney Green, Essex, and Badwell Ash, Suffolk, in eastern England, are attributed to soft-sediment deformation during an episode of regional thermokarst development. The involutions show a striking resemblance in morphology and size to thermokarst involutions within a palaeo-thaw layer at Crumbling Point, western arctic Canada. By analogy with the thermokarst involutions, the involutions in the Barham Soil are reinterpreted to have formed by loading during the melting of an ice-rich layer at the top of Anglian permafrost. This period of thermokarst development may have coincided with an episode of intra-Anglian climatic amelioration. Reinterpretation of the Barham Soil involutions implies that many other Pleistocene involutions in Britain may have formed during periods of thermokarst development rather than by active-layer cryoturbation.