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81.
Whereas refugees and larger immigrant groups’ integration in the Norwegian labour market has received considerable research attention, less is known about the labour market integration of small, non-refugee immigrant groups from West African countries such as Ghana. The purpose of the article is to examine the role of social networks and social identities for the differentiated labour market integration outcomes among Ghanaian immigrants in the city of Bergen. Based on data produced through in-depth interviews, participant observation and informal conversations, the authors argue that Ghanaian immigrants’ ability to obtain jobs is determined by more than simply having the appropriate educational and language qualifications, and largely depends on having favourable social identities and being embedded in social networks beyond the Ghanaian immigrant community. They find that those who mainly relied on Ghanaian networks found it difficult to circumvent labour market hindrances and they predominantly obtained menial jobs. The authors conclude that Norwegian job-seekers networks played a crucial role in the immigrants’ opportunities and for potential Norwegian employers’ perception of their employability, especially in professional and semi-professional jobs.  相似文献   
82.
83.
Throughout the last 1.1 million years repeated glaciations have modified the southern Fennoscandian landscape and the neighbouring continental shelf into their present form. The glacigenic erosion products derived from the Fennoscandian landmasses were transported to the northern North Sea and the SE Nordic Seas continental margin. The prominent sub‐marine Norwegian Channel trough, along the south coast of Norway, was the main transport route for the erosion products between 1.1 and 0.0 Ma. Most of these erosion products were deposited in the North Sea Fan, which reaches a maximum thickness of 1500 m and has nearly 40 000 km3 of sediments. About 90% of the North Sea Fan sediments have been deposited during the last 500 000 years, in a time period when fast‐moving ice streams occupied the Norwegian Channel during each glacial stage. Back‐stripping the sediment volumes in the northern North Sea and SE Nordic Seas sink areas, including the North Sea Fan, to their assumed Fennoscandian source area gives an average vertical erosion of 164 m for the 1.1–0.0 Ma time period. The average 1.1–0.0 Ma erosion rate in the Fennoscandian source area is estimated to be 0.15 mm a?1. We suggest, however, that large variations in erosion rates have existed through time and that the most intense Fennoscandian landscape denudation occurred during the time period of repeated shelf edge ice advances, namely from Marine Isotope Stage 12 (c. 0.5 Ma) onwards.  相似文献   
84.
Geotechnical and Geological Engineering - Grout curtains are commonly constructed under dams to reduce the seepage through the rock foundation. In the design of grout curtains, empirical methods...  相似文献   
85.
Computational Geosciences - Kriging is a standard method for conditioning surfaces to observations. Kriging works for vertical wells, but may produce surfaces that cross horizontal wells between...  相似文献   
86.
We provide the first documentation of tectonic deformation resulting from a volcanic eruption on the island of Jan Mayen. Vertical displacement of about 14 m southwest of the stratovolcano Beerenberg is associated with an eruption in ad 1732 on its southeastern flank. The age of the uplift event is bracketed by radiocarbon-dated driftwood buried by material deposited due to uplift, and by tephra from this eruption. Constraints, inferred from radiocarbon ages alone, allow for the possibility that uplift was completed prior to the ad 1732 eruption. However, the occurrence of tephra in the sediment column indicates that some displacement was ongoing during the eruption but ceased before the eruption terminated. We attribute the tectonic deformation to intrusion of shallow magma associated with the volcanic eruption. Our results complement previous studies of volcanic activity on Jan Mayan by providing precise age constraints for past volcanic activity. Also, it raises new hypotheses regarding the nature, timing and prevalence of precursor tectonic events to Jan Mayan eruptions. The uplift caused the complete isolation of a coastal lake by closing its outlet to the sea, thus landlocking the facultative migratory fish species Arctic charr (Salvelinus alpinus).  相似文献   
87.
Prütz  Ruben  Månsson  Peter 《Natural Hazards》2021,108(2):1807-1834
Natural Hazards - Fluvial floods can cause significant damages and are expected to increase in magnitude and frequency throughout the twenty-first century due to global warming. Alongside hazard...  相似文献   
88.
The influence on the spinel structure of Fe3+ → Cr substitution was studied in flux-grown synthetic single crystals of the magnesiochromite–magnesioferrite (MgCr2O4–MgFe2O4) solid solution series. Samples were analysed by single-crystal X-ray diffraction, electron microprobe analyses, optical absorption and Mössbauer spectroscopy. With the exception of iron-poor samples (3–12 mol-% MgFe2O4), optical absorption and Mössbauer spectra show that iron occurs almost exclusively as trivalent Fe in the present samples. A very intense and broad absorption band at ca 7,800 cm?1 dominates the optical absorption spectra of samples with higher Fe-contents. The appearance of this band is related to a distinct structural disorder of Fe3+ and a development of magnetic ordering as demonstrated by Mössbauer spectra. Profound composition-related changes are observed in the Mössbauer spectra, which are magnetically unsplit in the range 2–41 mol-% magnesioferrite, but become magnetically split in the range 59–100 mol-% magnesioferrite. Structural parameters a 0 and M–O increase with magnesioferrite content and inversion degree, while u and T–O decrease. Our study confirms the previously reported (Lavina et al. 2002) influence of Fe3+ at the M site on T–O bond lengths in the spinel structure.  相似文献   
89.
Long-term summer temperature variations in the Pyrenees   总被引:4,自引:0,他引:4  
Two hundred and sixty one newly measured tree-ring width and density series from living and dry-dead conifers from two timberline sites in the Spanish Pyrenees were compiled. Application of the regional curve standardization method for tree-ring detrending allowed the preservation of inter-annual to multi-centennial scale variability. The new density record correlates at 0.53 (0.68 in the higher frequency domain) with May–September maximum temperatures over the 1944–2005 period. Reconstructed warmth in the fourteenth to fifteenth and twentieth century is separated by a prolonged cooling from ∼1450 to 1850. Six of the ten warmest decades fall into the twentieth century, whereas the remaining four are reconstructed for the 1360–1440 interval. Comparison with novel density-based summer temperature reconstructions from the Swiss Alps and northern Sweden indicates decadal to longer-term similarity between the Pyrenees and Alps, but disagreement with northern Sweden. Spatial field correlations with instrumental data support the regional differentiation of the proxy records. While twentieth century warmth is evident in the Alps and Pyrenees, recent temperatures in Scandinavia are relatively cold in comparison to earlier warmth centered around medieval times, ∼1450, and the late eighteenth century. While coldest summers in the Alps and Pyrenees were in-phase with the Maunder and Dalton solar minima, lowest temperatures in Scandinavia occurred later at the onset of the twentieth century. However, fairly cold summers at the end of the fifteenth century, between ∼1600–1700, and ∼1820 were synchronized over Europe, and larger areas of the Northern Hemisphere.  相似文献   
90.
Flood hazard in Hungary: a re-assessment   总被引:1,自引:0,他引:1  
Some decades ago the concept of flood hazard in the Carpathian Basin was interpreted solely as riverine flood hazard, mostly restricted to the Tisza and Danube Rivers, and was closely associated with the impacts of river flow regulation in the second half of the 19th century. Recent assessments, however, allow us to outline a more diverse picture. Climate change is predicted to bring about both an increase in the frequency of droughts and excessive rainfall events, resulting in irregulaties in the water regimes of rivers in Hungary. Excess water hazard from raised groundwater levels is found to affect much larger areas than previously thought. Recent strongly localized cloudbursts, point to the increasing significance of flash floods.Riverine flooding and excess water hazard are more common in lowlands, whereas flash flood hazards are primarily, but not exclusively, affect the mountainous and hilly regions of the country. This paper intends to assess the relative importance of the three types of inundation hazard analyzed and to illustrate their overall spatial occurrences by microregions on a map series.  相似文献   
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