Comment on Special Issue on Geostatistics with Guest Editor A. G. Journel     

Kyrre Bratvedt  Erik Bølviken  Tore Gimse  Helge Holden  Lars Holden  Ragnar Knarud 《Mathematical Geology》1998,30(2):245-246

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Deglaciation history and post-glacial mass movements in Balsfjord, northern Norway     

Matthias Forwick  Tore O. Vorren 《Polar research》2002,21(2):259-266

The deglaciation history of Balsfjord, northern Norway, and post-glacial mass movement events were investigated. Radiocarbon dates indicate that the Balsfjord glacier retreated from the Tromsø–Lyngen moraines about 10.4 ¹⁴C Ky BP. Between ca. 10.3 ¹⁴C Ky BP and 9.9 ¹⁴C Ky BP, deposition of a distinct end moraine–the Skjevelnes moraine–in the central part of Balsfjord occurred. The transition from glacimarine to open marine sedimentary environment took place before 9.6 ¹⁴C Ky BP. Between ca. 9.5 ¹⁴C Ky BP and 8.4 ¹⁴C Ky BP, at least one local and three regional mass movement events occurred. After this period, no gravity flow activity is preserved in the cores. The high frequency of mass movements in the early post-glacial period is presumed to be due to fast sea level changes and/or tectonic activity induced by rapid isostatic uplift.  相似文献   

Environmental Geology     

Reijo Salminen Anne Kousa Rolf Tore Ottesen Olle Selinus Eiliv Steinnes Timo Tarvainen Bjoern OEhlander 《《幕》》2008,31(1):155-162

The mining environment, medical geology and urban geochemistry form a group of related scientific disciplines that have developed strongly during recent years in the Nordic countries. Modern legislation controls the environmental issues. Close co-operation of researchers and legislators has improved the quality and safety of life in the societies of the Nordic countries. In mining environmental studies, methods that are suitable in Arctic conditions have been developed; in medical geology, the input from the Nordic countries has made it an appreciated scientific discipline throughout the world, and in the case of the urban environment, methods developed by our geochemists have especially improved the health conditions, particularly of children.  相似文献   

Flow behaviour of the submarine glacigenic debris flows on the Bear Island Trough Mouth Fan, western Barents Sea   总被引：3，自引：0，他引：3  

Jan Sverre Laberg  & Tore O. Vorren 《Sedimentology》2000,47(6):1105-1117

Using 3·5 kHz high-resolution seismic data, gravity cores and side-scan sonar imagery, the flow behaviour of submarine, glacigenic debris flows on the Bear Island Trough Mouth Fan, western Barents Sea was studied. During their downslope movement, the sediments within the uppermost part of the debris flows (<3 m) are inferred to have been deformed as a result of the shear stress at the debris–water interface. Thus, the uppermost part of the flow did not move downslope as a rigid plug. If present, a rigid part of the flow was located at least some metres below the surface. At c . 1000 to at least 1600 m water depth, the debris flows eroded and probably incorporated substrate debris. Further downslope, the debris flows moved passively over substrate sediments. The hypothesis of hydroplaning of the debris flow front may explain why the debris flows moved across the lower fan without affecting the underlying sediments. Detailed morphological information from the surface of one of the debris flow deposits reveals arcuate ridges. These features were probably formed by flow surge. Hydroplaning of the debris flow front may also explain the formation of flow surge. The long runout distance of some of the large debris flows could be due to accretion of material to the base of the debris flow, thereby increasing in volume during flow, and/or to hydroplaning suppressing deceleration of the flow.  相似文献   

What Determines the Amplitude of ENSO Events?          下载免费PDF全文

WANG Yu-Xing  YANG Hai-jun  Tore FUREVIK 《大气和海洋科学快报》2013,6(2):90-96

In this paper, the dynamic effect of oceanic upwelling on the intensity of El Nio-Southern Oscillation (ENSO) is studied using a simple coupled model (Zebiak-Cane Model). The term balance analysis in the temperature variability equation shows that the anomalous upwelling of the mean vertical temperature gradient and the mean advection of the anomalous meridional temperature gradient are the two of most important factors that determine the intensity of ENSO events, in which the "vertical oceanic heat flux" in the eastern equatorial Pacific (EEP) is the primary influencing factor. The lag correlation between "vertical heat flux (VHF)" and ENSO intensity shows that the highest correlation occurs when the former leads the latter by one to two weeks. The VHF is positively correlated with the background thermocline strength in the EEP, and an increase of both could result in strong ENSO variability. Comparison of the forced and coupled experiments suggests that the coupled process can affect both the intensity and frequency of ENSO.  相似文献   

Mechanisms for decadal scale variability in a simulated Atlantic meridional overturning circulation   总被引：1，自引：1，他引：0  

I. Medhaug  H. R. Langehaug  T. Eldevik  T. Furevik  M. Bentsen 《Climate Dynamics》2012,39(1-2):77-93

Variability in the Atlantic Meridional Overturning Circulation (AMOC) has been analysed using a 600-year pre-industrial control simulation with the Bergen Climate Model. The typical AMOC variability has amplitudes of 1?Sverdrup (1 Sv?=?10⁶?m³?s^?1) and time scales of 40–70?years. The model is reproducing the observed dense water formation regions and has very realistic ocean transports and water mass distributions. The dense water produced in the Labrador Sea (1/3) and in the Nordic Seas, including the water entrained into the dense overflows across the Greenland-Scotland Ridge (GSR; 2/3), are the sources of North Atlantic Deep Water (NADW) forming the lower limb of the AMOC’s northern overturning. The variability in the Labrador Sea and the Nordic Seas convection is driven by decadal scale air-sea fluxes in the convective region that can be related to opposite phases of the North Atlantic Oscillation. The Labrador Sea convection is directly linked to the variability in AMOC. Linkages between convection and water mass transformation in the Nordic Seas are more indirect. The Scandinavian Pattern, the third mode of atmospheric variability in the North Atlantic, is a driver of the ocean’s poleward heat transport (PHT), the overall constraint on northern water mass transformation. Increased PHT is both associated with an increased water mass exchange across the GSR, and a stronger AMOC.  相似文献   

Distinct petrographic responses to basin reorganization across the Triassic–Jurassic boundary in the southwestern Barents Sea     

Lina H. Line  Reidar Müller  Tore G. Klausen  Jens Jahren  Helge Hellevang 《Basin Research》2020,32(6):1463-1484

A general shift towards higher mineralogical and textural maturity changes the reservoir character across the Triassic–Jurassic transition in the southwestern Barents Sea basin (SWBSB), largely affecting the hydrocarbon prospectivity in the region. Petrographic and geochronological provenance data presented in this paper suggest that the shift from mineralogically immature to mature sandstones initiated during the deposition of the Norian–Rhaetian Fruholmen Formation, and varies with basin location. Strong contrasts between the Fruholmen Formation and underlying formations are associated with proximity to the rejuvenated Caledonian and Fennoscandian hinterlands and are mainly restricted to the southern basin margins. In the basin interior, subtle petrographic variations between the Fruholmen Formation and older Triassic sandstones reflect a distal position relative to the southern hinterland. The long-lived misconception of a regional compositional contrast in the Arctic at the turn of the Norian can be attributed to higher sampling frequency associated with hydrocarbon exploration activity along the southern basin margins, and masking by increased annual precipitation and subsequent reworking during the Jurassic. Geothermal signatures and rearrangement of ferric clay material across the Carnian–Norian transition support a recycled origin for the Fruholmen Formation in the basin interior. As the closest tectonically active region at the time, the Novaya Zemlya fold-and-thrust belt represents the best provenance candidate for polycyclic components in Norian–Rhaetian strata. In addition to recycling in the hinterland during the Late Triassic, local erosion of exposed intrabasinal highs and platforms at the Triassic–Jurassic transition represents a second process where thermodynamically unstable mineral components originally sourced from the Uralides may be removed. Textural and mineralogical modification may also have occurred in marginal-marine depositional environments during periods with elevated sea level. Mature sediment supply from the rejuvenated hinterland in the south, multiple cycles of reworking and gradual accumulation of polycyclic grains have likely led to the extreme compositional maturity registered in the Tubåen, Nordmela and Stø formations in the SWBSB. It is likely that increased annual precipitation since the latest Carnian had an amplifying effect on sandstone maturation across the Triassic–Jurassic boundary, but we consider the effect to be inferior compared to provenance shifts and reworking. Findings from this study are important for understanding compositional and textural maturity enhancement processes in siliciclastic sedimentary basins.  相似文献   

MÖssbauer spectroscopy,x-ray diffraction,and electron microprobe analysis of the New Haifa meteorite     

Yassir A. ABDU  Tore ERICSSON 《Meteoritics & planetary science》1997,32(3):373-375

Abstract— MÖssbauer spectroscopy, x-ray diffraction (XRD) measurements, and electron microprobe analysis (EMPA) have been carried out for the investigation of a newly fallen Sudanese meteorite named New Haifa. The room temperature MÖssbauer spectrum is fitted with three sextets and two doublets. The sextets are assigned to Fe in troilite, kamacite, and taenite, and the two doublets are assigned to Fe²⁺in olivine and pyroxene (no Fe³⁺was found). The microprobe trace of Ni concentration across a kamacite-taenite-kamacite area shows a high-Ni concentration at the interfaces between kamacite and taenite. From the microprobe analysis, olivine appears to have a constant composition, whereas pyroxene has a varying composition. The mole fractions of the Fe end members of olivine (fayalite) and pyroxene (ferrosilite) are found to be 23.5% and 23.2%, respectively. Accordingly, the New Haifa meteorite is classified as an ordinary L-type chondrite.  相似文献   

Quaternary of Norden     

Barbara Wohlfarth Svante Bjoerck Svend Funder Michael Houmark-Nielsen Olafurlngolfsson Juha-Pekka Lunkka Jan Mangerud Matti Saarnisto Tore Vorren 《《幕》》2008,31(1):73-81

The Nordic countries have experienced multiple glaciations and intervening interglacials during the last ca. 2.5-3 million years. Although evidence from Greenland and Iceland shows that ice sheets started to expand some time before 3 Ma, little is known about the glaciations and intervening interglacials older than the last Glacial Maximum due to repeated phases of glacial erosion and reworking. The extensive Saalian glaciation （c. 140 ka BP） contributed to high sea levels in Greenland and in the Baltic area during the early part of the last interglacial （Eemian）. Temperatures were about 5 ℃ higher during the Eemian than they are today and the Greenland ice sheet was reduced to about half of its present size, causing globally higher sea levels than we have today. Ice extent in Fennoscandia was restricted during early Weichselian stadials, but middle Weichselian ice advances in Scandinavia reached as far as Denmark. During the Last Glacial Maximum, large ice sheets were present in all Nordic countries and coalesced with neighboring ice sheets. Deglaciation commenced around 17-15 ka BP in most areas and was promoted by rapidly rising global sea level and glacial isostasy. The Younger Dryas cold event（c. 12.6-11.5 ka BP） is seen as a short-term re-advance, still-stand or fluctuation of land-based ice sheet margins. Around 7-9 ka BP ice sheets had disappeared or had attained their present size. While uplift is still going on in some regions, others are subject to submergence. The different stages of development of the Baltic Sea are an example of how the intricare interplay between glacial eustasy and isostasy influences sedimentation, basin size and drainage patterns.  相似文献   

PCB contamination from sampling equipment and packaging     

Malin Andersson  Rolf Tore Ottesen  Morten Jartun  Ola Eggen  Ann-Christine Enqvist 《Applied Geochemistry》2012

Work reported in this paper suggests that there are cases of contamination of soil and water samples by polychlorinated biphenyls (PCB) from paper and plastic packaging. Soil samples, which have been stored in paper bags for more than 20 years, share a similar congener distribution as the bags. Analyses showed a predominance of light congeners. PCB-analyses of water also indicate that water samples could be contaminated by plastic packaging. All analytical results of solid material packaging, as well as soil stored in the packaging, show a high relative amount of light weight PCB congeners. The paper bags that were analysed are made of strong paper and very popular among geochemists because of their watertight quality. These paper bags were manufactured more than 20 years ago. The plastic packaging that was analysed was produced in 1997 and 2008. The analyses of plastic and paper show that the raw material that has been used in the production at different times contains a wide concentration range of PCB. Re-sealable plastic bags, which contained the highest levels of PCB of the plastic material, are used by researchers world-wide as sampling bags for soils and sediments. This paper raises an important issue that packaging may potentially contaminate the samples that they hold.  相似文献