A comparison of archaeointensity results from Chinese ceramics using microwave and conventional Thellier's and Shaw's methods

Palaeo- and archaeointensity determinations of the geomagnetic field are limited by mineralogical alteration that may occur when samples are heated in the laboratory to produce a TRM ( Thellier & Thellier 1959 ; Shaw 1974 ). By using microwave excitation of the magnetic grains we have been able to create a TRM without significantly heating the bulk samples, thereby avoiding thermal alteration ( Walton et al . 1993 ; Shaw et al . 1996 ). When applied to Peruvian ceramics in a manner analogous to the standard Thellier method, the microwave technique was found to reduce the scatter dramatically in the archaeointensity results ( Shaw et al . 1996 ). In the present study we apply this microwave technique to a collection of Chinese ceramics covering the time interval 2700–7500  yr BP. These ceramics have already been investigated using adaptations of both Thellier's ( Coe 1967 ) and Shaw's ( Rolph & Shaw 1985 ) palaeointensity methods ( Yang et al . 1993a ). Although an acceptable agreement was found between those two methods, the equivalent virtual axial dipole moments (VADMs) were significantly lower than for the global model of McElhinny & Senanayake (1982 ). The present study, using the microwave technique with cooling-rate correction, has provided more consistent VADMs, and is much closer to the global model.     

Crustal structure beneath exposed accreted terranes of Southern Alaska

Summary. The crustal structure beneath the exposed terranes of southern Alaska has been explored using coincident seismic refraction and reflection profiling. A wide-angle reflector at 8–9 km depth, at the base of an inferred low-velocity zone, underlies the Peninsular and Chugach terranes, appears to truncate their boundary, and may represent a horizontal decollement beneath the terranes. The crust beneath the Chugach terrane is characterized by a series of north-dipping paired layers having low and high velocities that may represent subducted slices of oceanic crust and mantle. This layered series may continue northward under the Peninsular terrane. Earthquake locations in the Wrangell Benioff zone indicate that at least the upper two low-high velocity layer pairs are tectonically inactive and that they appear to have been accreted to the base of the continental crust. The refraction data suggest that the Contact fault between two similar terranes, the Chugach and Prince William terranes, is a deeply penetrating feature that separates lower crust (deeper than 10 km) with paired dipping reflectors, from crust without such reflectors.     

AVERAGE GLOBAL LOCATIONS

Global distributions are commonly described by maps and tables which emphasize the dispersion of a distribution. The Mean Spheroidal Center (M.S.C.) defines the average location of a world distribution. It is an objectively determined point within the sphere's surface. The M.S.C. calculations are demonstrated using the world's 25 largest cities in each of four time periods.     

Loose threads: The translocal making of public space policy in Hanoi

This paper analyses the recent developments in public space policy in the city of Hanoi, Vietnam. It has three aims. The first is to look at a potentially progressive urban policy in contrast to most work on ‘policies in motion’ that has primarily been concerned with neoliberal policies. The second is to put the process of public space policymaking in Hanoi in historical and cultural perspective. We therefore describe public space in Hanoi as historically constituted by different layers of meaning and physical urban patterns. The paper's third aim is to analyse the translocal connections involved in a policy that is still in the making, and therefore characterized by a series of ‘loose threads’. We show how different types of connections – policy mobility, topological relations and inter‐referencing – relate Hanoi to multiple locales elsewhere. The conclusion reflects on the ‘politics of reception’ showing how analysing a policy in the making develops a critical analysis of policies in motion.     

Södra Finlands blocksänkor

Söderman, G.: Södra Finlands blocksänkor. Geografisk Tidsskrift, 82, 77–81, November 1. 1982.

Map analysis and field inventory show that there are about 20000 boulder depressions in Finland south of 64°N. The features are most common in blocky till areas close to fracture zones in the bedrock. The depressions range in altitude from above the highest shore-line down to 25–30 m above present sea-level. They are youngest in the NW part. Some depressions show surface patterns.

SAMMANDRAG

Blocksänkor är frostmarksformer med en huvudsakligen vertikal sortering som ett resultat av differentiell uppfrysning av blockrikt utgångsmaterial. De framställer inga klimatiska kriteria om utbildningstid och -förhållanden. Däremot här de till områden med sasängbetonad frostaktivitet, och om ej inskränkta till nedisade omräden, trots typiska fär dessa. Blocksänkorna är den mest utbredda och största frostmarksform inom den fennoskandiska skogsregionen i dag.     

Human and Environmental Factors Affect Patterns of Crop Diversity in an Ethiopian Highland Agroecosystem

The Ethiopian highlands are a center of diversity for numerous globally important crops. Heterogeneous landscapes, traditional agricultural practices, and inaccessibility have created and maintained diverse subsistence agroecosystems. We surveyed sixty-three farms in twelve communities of the Gamo highlands and found high levels of on-farm diversity of crop species and varieties. The extent and nature of this diversity are related to both ecological factors, namely elevation, and anthropogenic factors such as land-use history, accessibility to markets and extension, and strength and scale of farmer exchange networks. These human landscape features have the potential to both enhance and mediate effects of elevation and other environmental factors on crop diversity. The interaction of environmental and anthropogenic forces on the diversity of crops grown by farmers affects the strategies farmers employ to adapt their farming to changing conditions.     

Authorship,Collaboration, and Gender: Fifteen Years of Publication Productivity in Selected Geography Journals

In academia, publication productivity, defined as the number of peer-reviewed articles published and the frequency of citations, is a primary factor in the assessment of tenure and promotion. One of the most cited gender differences in academia is the “productivity puzzle,” which suggests that women publish less than men, thereby affecting every aspect of a woman's academic career. Peer-reviewed articles published in the Annals of the Association of American Geographers (Annals) and The Professional Geographer (PG) between 1995 and 2006, and in four subdisciplinary journals between 2005 and 2009, as well as citation reports, were used to explore whether gender differences are present in publication productivity. Gender differences were evident in the proportion of women authors, the frequency of collaboration, and the number of citations across a broad range of prestigious geographic journals. For all journals studied, women were underrepresented, especially in the authorship positions that equate to notions of respect and merit. Although the number of collaborative articles increased during the study period, single-authored papers are the dominant mode of publication for both men and women for most geographic journals. The authorship patterns for frequently cited articles generally mirror those for all articles. Because the frequency of collaborative publication was high for women, the dual trends of a general increase in publication collaboration and increasing participation of women in academic geography bodes well for increased female productivity as it relates to publishing. Nevertheless, it is important to note that, currently, males as lead or single authors represent the predominant voice of geography within the journals examined in this study.     

Ethnic and Racial Differences in Tornado Hazard Perception,Preparedness, and Shelter Lead Time in Tuscaloosa

The 27 April 2011 EF4 Tuscaloosa tornado directly impacted more than 50,000 residents, causing forty-five fatalities within the city and sixty-five in total. It was a rare urban tornado with varying impacts on the three major ethnic and racial groups within the city. A hybrid survey and interview of open-ended and closed questions was conducted with 211 Tuscaloosa area residents in a two-week period after the tornado. Results indicate significant differences in risk perception, preparedness, and shelter lead time among the three ethnic and racial groups. Furthermore, results were still significant for perception after controlling for the effects of age, education, and experience.     

Is GIS appropriate technologyquest;

Abstract

Appropriate technology (AT) has become an integral part of the programmes for decentralized regional development in the Third World. ‘Appropriate’ techniques are usually low in capital costs; they can be maintained without a high level of expertise; and they do not involve patents, expensive copyrights and royalties. By these criteria a commercial geographical information system (GIS) is not an appropriate technology to be used in decentralized development However, the use of local renewable resources involves the adoption of end-use analysis for matching end-uses to specific sources so as to minimize the consumption of material and energy (i.e., minimize entropy). This matching requires much information which leads to what may be called the 'information-entropy trade-off; minimization of entropy requires an inverse increase in information. In this respect computers and GIS have an important contribution to make to decentralized regional planning. Drawing on a case study in Sri Lanka, this paper presents some ideas on how to incorporate GIS into local-level planning information systems.