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SHANNON O'LEAR 《Geographical review》1997,87(2):275-290
ABSTRACT. The use of e-mail by a grassroots activist group that straddles the Estonian-Russian border transcends political boundaries and provides ready connections to people in distant places. Activists create a perceived space of resistance in a supportive network that is stretched across space. This network of concern, defined by the physical space in which these activists work and by the strong communicative connections among them, was created to overcome continued environmental mismanagement and remove cultural barriers to cooperation. E-mail communication has enabled an ongoing influence on environmental policy in Estonia and Russia. This circumstance of a collaborative e-mail network created by grassroots activists to aid political work is a testament to how communication technology has expanded for the purpose of strengthening previously silenced voices in a regional and political context. 相似文献
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On the south‐west coast of Vancouver Island, Canada, sedimentological and ichnological analysis of three beach–shoreface complexes developed along a strait margin was undertaken to quantify process–response relations in straits and to develop a model for strait‐margin beaches. For all three beaches, evidence of tidal processes are expressed best in the lower shoreface and offshore and, to a lesser extent, in the middle shoreface. Tidal currents are dominant offshore, below 18 m water depth (relative to the mean spring high tide), whereas wave processes dominate sediment deposition in the nearshore (intertidal zone to 5 m water depth). From 18 to 5 m water depth, tidal processes decrease in importance relative to wave processes. The relatively high tidal energy in the offshore and lower shoreface is manifest sedimentologically by the dominance of sand, of a similar grain size to the upper shoreface/intertidal zone and, by the prevalence of current‐generated structures (current ripples) oriented parallel to the shoreline. In addition, the offshore and lower shoreface of strait‐bound beach–shoreface complexes are recognized ichnologically by traces typical of the Skolithos Ichnofacies. This situation contrasts to the dominantly horizontal feeding traces characteristic of the Cruziana Ichnofacies that are prevalent in the lower shoreface and offshore of open‐coast (wave‐dominated) beach–shorefaces. These sedimentological and ichnological characteristics reflect tidal influence on sediment deposition; consequently, the term ‘tide‐influenced shoreface’ most accurately describes these depositional environments. 相似文献
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Development of spatially diverse and complex dune-field patterns: Gran Desierto Dune Field, Sonora, Mexico 总被引：5，自引：0，他引：5
CARRIE BEVERIDGE GARY KOCUREK RYAN C. EWING NICHOLAS LANCASTER† P. MORTHEKAI‡ ASHOK K. SINGHVI‡ SHANNON A. MAHAN§ 《Sedimentology》2006,53(6):1391-1409
The pattern of dunes within the Gran Desierto of Sonora, Mexico, is both spatially diverse and complex. Identification of the pattern components from remote‐sensing images, combined with statistical analysis of their measured parameters demonstrate that the composite pattern consists of separate populations of simple dune patterns. Age‐bracketing by optically stimulated luminescence (OSL) indicates that the simple patterns represent relatively short‐lived aeolian constructional events since ～25 ka. The simple dune patterns consist of: (i) late Pleistocene relict linear dunes; (ii) degraded crescentic dunes formed at ～12 ka; (iii) early Holocene western crescentic dunes; (iv) eastern crescentic dunes emplaced at ～7 ka; and (v) star dunes formed during the last 3 ka. Recognition of the simple patterns and their ages allows for the geomorphic backstripping of the composite pattern. Palaeowind reconstructions, based upon the rule of gross bedform‐normal transport, are largely in agreement with regional proxy data. The sediment state over time for the Gran Desierto is one in which the sediment supply for aeolian constructional events is derived from previously stored sediment (Ancestral Colorado River sediment), and contemporaneous influx from the lower Colorado River valley and coastal influx from the Bahia del Adair inlet. Aeolian constructional events are triggered by climatic shifts to greater aridity, changes in the wind regime, and the development of a sediment supply. The rate of geomorphic change within the Gran Desierto is significantly greater than the rate of subsidence and burial of the accumulation surface upon which it rests. 相似文献
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SHANNON O'LEAR 《The Geographical journal》2007,173(3):207-223
After considering how well Azerbaijan's economy follows the trajectory of a 'resource curse' state, this paper investigates the political dimensions of the resource curse evident in Azerbaijan. Of particular interest is how Azerbaijan appears to establish external and internal political legitimacy. These dimensions of sovereignty are not necessarily balanced or present in equal measure. The paper assesses the recent transition in leadership in Azerbaijan as well as Azerbaijan's interactions with, and assessment by, the international community. Additionally, national survey data provide insights into public concerns, satisfaction with government policy, and views on democracy and freedom of expression. The paper concludes that at present there appears to be sufficient public expectation for future benefits, combined with institutional stability, to stave off widespread political instability for the time being. 相似文献
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Results are presented from the on-orbit calibration of the Jason Microwave Radiometer (JMR). The JMR brightness temperatures (TBs) are calibrated at the hottest and coldest ends of the instrument's dynamic range, using Amazon rain forest and vicarious cold on-Earth theoretical brightness temperature references. The retrieved path delay values are validated using collocated TOPEX Microwave Radiometer and Radiosonde Observation path delay (PD) values. Offsets of 1–4 K in the JMR TBs and 8–12 mm in the JMR PDs, relative to TMR measurements, were initially observed. There were also initial TB offsets of 2 K between the satellite's yaw state. The calibration was adjusted by tuning coefficients in the antenna temperature calibration algorithm and the antenna pattern correction algorithm. The calibrated path delay values are demonstrated to have no significant bias or scale errors with consistent performance in all nonprecipitating weather conditions. The uncertainty of the individual path delay measurements is estimated to be 0.74 cm ± 0.15, which exceeds the mission goal of 1.2 cm RMS. 相似文献
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