Lateral benches of glacial valleys in the Svartisen area of North Norway

Abstract

Bennett, R. G. Lateral benches of glacial valleys in the Svartisen area of North Norway. Norsk geogr. Tidsskr. 21, 1967, 254–268.

Some irregular valley benches in the Svartisen area are described and their formation is discussed. It is found that some are structurally controlled, while others are features of glacial and extra-glacial erosion. The conditions under which the larger benches were formed were so different that no genetic classification of these features is possible.     

Digital Terrain Modelling of the Surface and Bed Topography of the Glacier Austre Okstindbreen, Okstindan, Norway

Twentieth-century changes in Norwegian glaciers have been pronounced, but the different geometries and dynamics of the glaciers have caused different responses to similar climatic changes. Close to the Arctic Circle, all the glaciers of Svartisen, the largest ice-covered area of northern Scandinavia, have retreated since the beginning of the century. However, several of the smaller glaciers which end at relatively high altitude have experienced both periods of advance and periods of retreat since the mid-1960s. The mass balance of Engabreen, the largest of the West Svartisen glaciers, was positive in 21 of the 27 years to 1995–96. The sizes of most of the glaciers of the Okstindan area, 60 km south-east of Svartisen, have also decreased throughout the twentieth century, but Corneliussens Bre, a small glacier at the eastern side of the massif, has been advancing since 1970. The areas supplying some of the southern glaciers of Okstindan have been reduced as a result of changes in ice thickness at high altitude. Studies of glacier change are aided by the use of digital terrain models (DTMs). Triangular irregular network DTMs of the surface and bed topography of the largest of the Okstindan glaciers, Austre Okstindbreen, have been used in studies of mass-balance variations and changing surface flow patterns between 1976 and 1995.     

Våre Breers Tilbakegang

For Svartisen har jeg sokt å foreta en liknende beregning av bremassens minking, som den jeg har foretatt for Jostedalsbreen (Norsk Geografisk Tidsskrift, Bd.VIII, H. 8, 1941, side 273 ff.). Jeg har herunder brukt vannforingsmålinger i Fykanåen i Glomfjord, som har tillop f ra et ganske betydelig omráde, 90 km², av Svartisen og til sammenlikning målinger i Rosåen, som ligger sonnafor og i Sundsfjordelven nordafor.     

Frost Shatter and Glacial Erosion under the margins of Østerdalsisen,Svartisen

Abstract

Bennett, Roger G. (1968) Frost Shatter and Glacial Erosion under the Margins of Østerdalsisen, Svartisen. Norsk geogr. Tidsskr. 22, 209–213 Subglacial.observations on the glacier Østerdalsisen at Svartisen, North Norway, on two occasions during the winters of 1965 and 1967 showed a marked increase in the amount of debris transported by the glacier in comparison with that carried in the summer. On closer examination, frost shatter on the lee sides of rock steps in the immediate lee of the ice-rock contact was found to be responsible for the loosening of fragments, which the glacier was then able to pluck from the wall.     

Flatisen,Svartisen: A Norwegian glacier in decline

ABSTRACT

The advance and retreat of glaciers, influenced by changes of local and regional climates, can result in dramatic landscape changes. The article, which follows up previous documentation of long-term studies at Svartisen, deals with changes of Flatisen: at the end of the 19th century, this was one of the largest glaciers of West Svartisen, and was supplied by accumulation areas that rose to > 1400 m a.s.l. It crossed the river Glomåga and ascended to 100 m above the valley floor. The river had a subglacial course until the 1920s. A proglacial lake, formed in front of the glacier in the 1930s and became larger throughout the rest of the 20th century. Changes of Flatisen between 1957 and 1990 were monitored during visits to the glacier. After the retreating front became inaccessible by land, photographs were taken. Early this century, the glacier retreated from the lake. A helicopter reconnaissance in July 2017 revealed that the surface was almost wholly below 1000 m a.s.l., the local equilibrium line altitude of recent years. Without a permanent accumulation zone, Flatisen is likely to disappear within the first half of the present century.     

The paleocurrents and morphology of Pikhåggrottene,Svartisen, North Norway

The Pikhågan caves at Svartisen, North Norway, are described and then analysed using passage morphology and scallop morphometry. The caves consist of a multilevel network of essentially horizontal phreatic tubes with a total length of 2,000 + m. Vadose elements account for only about 4% of the total passage lengths, while paragenetic roof alterations arc more common (?10%). Palcocurrcnt direction and flow rates as deduced from scallops suggest a uniform network flow southwards through the system, which also fits well with hydraulic laws for tube networks. This model requires a hydraulic conductivity between entrances formed by glacial truncation. Evidence of a subsequent sediment fill and paragenetic incision of roof half-tubes is demonstrated. These phases were followed by a lowering of the local watertable from above 610 m to about 575 m, when a phase of high discharge occurred. If this shift of watertable was caused by bedrock erosion, it probably took place more than 220 ka ago. Subsequently the watertable was lowered further to its present level (<560 m). Two alternative origins are suggested: first, a possible pre-glacial genesis of the phreatic network in a paleic valley system, second, a possible sub-glacial genesis. The paragenetic phase is regarded as the most likely to have occurred subglacially, while the coarse sediment infilling and the high discharge regime arc associated with deglaciations. The previously proposed proglacial genesis of this phreatic cave system is rejected because of the present topography and because of the slow paleocurrent regime inferred from scallop measurements.     

中国沿海地区持续发展隐患浅论

根据作者实地考察,发现中国沿海地区经济势头迅猛增长中隐含不少重大问题,包括重复建设、急功近利、追求自我完善体系,与当代国际经济一体化的走势相背。由于防灾意识淡薄,环境问题突出,资金浪费严重,许多重大项目建设布局不合理。本文探讨了隐患形成机制及其防范对策。     

新区实践与城市发展理念新动向

20世纪90年代以来,我国城市新区发展突飞猛进,特别是浦东新区的成功更催化着这股热潮.纵观全国新区建设起点与规划,现代城市发展新理念发挥着重要作用,特别是生态文明、文化软实力、服务型政府等理念令人瞩目.以全国100多个城市新区的资料文献、统计数据、政府报告等为基础,发现城市发展新理念深刻影响着城市新区发展,城市新区就是我国城市发展新理念在城市中的实践.     

基于TIC的多时相遥感影像相对辐射归化处理

采用不变点群法(temporally invariant cluster,TIC),由两时相影像的NDVI点密度图确定两个TIC中心并建立辐射归化处理方程,对影像的NDVI进行相对辐射归化处理。与其它辐射归化处理方法相比,该方法简单、有效且精度高,对轻微的植被物候变化敏感且影像不变特征点较少时也能进行辐射归化处理,可有效应用于土地利用/覆盖、植被物候及景观等变化监测。     

'What Goes Around Comes Around': Informal Activities and Reciprocity Networks in Westport, New Zealand

The article reports the results of a survey into the informal activities of 47 households in the unemployment‐affected small town of Westport, New Zealand. Overall levels of household informal participation are found to be fairly high across all income groups. There is an abundance of informal resources in the surrounding area and a longstanding local culture encouraging participation. However, differentiated ‘established local’ and ‘new local’ reciprocity networks, reflecting broader scale processes of social and economic fragmentation, have emerged since a major round of state and private sector restructuring occurred in 1987.     

Logging Out: Forestry, Transport and the Health of Hokianga Communities

This paper reports on log transportation as a health-related issue in the Hokianga district of Northland at a time when forestry activity in the area is expanding and radical reforms to New Zealand's roading network have been proposed. Drawing on technical information and key informant interviews, the potential impacts of logging trucks on Hokianga roads are considered, the costs associated with forestry traffic are estimated, and the routes most likely to be affected are identified. Possible responses to the log transport problem are discussed, and it is concluded that rural communities such as Hokianga are vulnerable to both logging truck activity and changes in government policy.     

Minnesota—A Sketch

Abstract

This article reports the results of an exploratory project to determine the abilities of Grade 6 children to work with digital data. The research questions dealt with understanding what is digital data, understanding what is a pixel, and how digital data can be used, making a digital map, and using pixels to determine area on maps. The results of the project showed that the children in this study were able to work with digital data, and that there is potential for using digital data on the Grade 6 level in geography instruction.     

Population dynamics, socioeconomic change and land colonization in northern Jordan, with special reference to the Badia Research and Development Project area

The paper reports on preliminary observations from northern Jordan aimed at testing the view that people migrate from areas of relatively high potential for cultivation to the marginal semi-arid/arid frontier because of social differentiation, political factors or environmental constraints. Cultivated areas have been mapped from multi-date remotely sensed imagery, a typology of fields in the area has been constructed, and their dynamics between 1972 and 1992 analysed. In addition, semi-structured interviews with farmers attempted to understand the reasoning behind village growth, changing farming systems and cultivation practices. The findings are discussed in the context of the area's demography and national and regional shifts in economic policy.     

TREND SURFACE ANALYSIS OF GLACIALLY BURIED PLEISTOCENE ORGANIC DEPOSITS IN CENTRAL MICHIGAN*

Trend surfaces were determined and compared for the bedrock surface, two characteristics of the present topography, and 42 water well log reports of glacially buried carbonaceous horizons within drift from an area in central Michigan. Data almost certainly indicate that the glacially buried Pleistocene organic deposits represent two or more pre-Woodfordian paleosurfaces. Trend surface analysis of buried organic horizons may be useful for recognizing paleosurfaces and separating drift sheets in other areas with limited subsurface data.     

Detecting biophysical properties of a semi-arid grassland and distinguishing burned from unburned areas with hyperspectral reflectance

This paper examines the utility of hyperspectral remote sensing to detect fresh and dry biomass, water content and plant area index of burned and unburned grassland in southern California. Contrary to many previously published reports, the normalized difference vegetation index (NDVI, a vegetation greenness index) was not a good indicator of any of these important biophysical properties in either the burned or unburned area, especially after regeneration. Rather, the water band index (WBI, an index of water status in vegetation) showed better promise of estimating these biophysical properties in this semi-arid ecosystem. Despite the post-regeneration similarities in visual and harvested values of these two areas, we found that the full range of hyperspectral reflectance in ‘visible to infrared’ (400–1000 nm) wavelengths when used in a cluster analysis can readily differentiate the burned and unburned areas. This demonstrates the utility of hyperspectral remote-sensing in mapping subtle features that may not be detectable from conventional remote-sensing indices (e.g. NDVI) alone.     

珠江三角洲土地覆盖变化对地表温度的影响

由于经济的快速增长,1978年以来的25年中,珠江三角洲地区的土地覆盖变化,特别是城市扩展速度非常之快。通过把遥感和地理信息系统相结合,研究了土地覆盖变化及城市增长状况,并且评估了城市增长对地表温度的影响。利用陆地卫星多时段数据监测了土地利用和土地覆盖变化;通过陆地卫星热红外单波段反演了地表温度,研究了土地覆盖变化特别是城市增长对地表温度的影响。结果发现,珠江三角洲地区土地覆盖变化明显,城市增长显著且不平衡。城市的发展使城市化地区的地表温度提高了8.9K。研究表明,遥感和地理信息系统的结合,在监测和分析土地覆盖变化,特别是城市增长状况以及评估城市化对地表温度的影响方面,是十分有效的。     

日本人造陆地利用方向的演化

矿产资源贫乏,平原面积狭窄是日本谋求发展的重大障碍。向海洋扩展土地,追求土地的最佳利用方式,推动着日本填海造陆的历史,创造出日本列岛独具特色的海岸线景观。本文主要阐述日本人造陆地的发展历史,并具体介绍其人造陆地利用形态的发展变化特征。     

Precursory seismic quiescence in the Mudurnu Valley, North Anatolian fault zone, Turkey

The seismicity rate in the Mudurnu Valley of Turkey was studied using an earthquake catalogue that reports events homogeneously down to magnitude 2.3 for the years 1985–1989, and covers the area between latitudes 40.2° and 41.0°N, and longitudes 30.0° and 31.5°E. During this period the only two main shocks, M = 4.0 and M = 4.3, occurred on 1988 September 6 and 1988 December 9 within about 30km of each other. A highly significant seismic quiescence is evident in the area surrounding these main shocks, while the seismicity rate in the rest of the area covered by the catalogue remains constant. the quiescence becomes more pronounced the smaller the area around the main shocks that is studied. the smallest areas that can be studied contain about 60 earthquakes and have dimensions of approximately 25km on each side. the decreases in seismicity rates are 50–80 per cent depending on the volume and period used for defining the quiescence. the quiescence started in 1988 January and lasted about seven months, with approximately 4.5 months of normal activity separating it from the main shock of December. the precursor time of 12 months for an M = 4.3 main shock is similar to those observed in California. It is concluded that it is possible to resolve precursory quiescence before moderate and large earthquakes in the Mudurnu area with the existing seismograph network.     

Historical desertification of the Mu Us Sandy Land: A perspective from the Beidachi section

Historical desertification of the Mu Us Sandy Land is linked to both environmental changes and anthropogenic activities. This paper reports on an analysis of grain size parameters as indicative of such changes in the southwestern area of the Mu Us Sandy Land. Combined with analysis of chronologies and historical records, our results indicate that Beidachi Lake and a nearby seasonal river have retreated continuously in history and that sand dunes appeared at approximately the end of the Ming dynasty. This study sheds new light on the understanding of spatial-temporal changes of the interior Mu Us Sandy Land in history and has great significance in revealing environmental changes of the interior region of the Mu Us Sandy Land.