Direct and indirect methods for groundwater investigations: A case-study of MRS and VES in the southern part of Sweden   总被引：1，自引：0，他引：1  

Kamhaeng Wattanasen  Sten-ke Elming 《Journal of Applied Geophysics》2008,66(3-4):104

Magnetic Resonance Sounding (MRS) has been successfully tested for detecting groundwater in two areas in southern Sweden. Measurements of Schlumberger VES have been conducted in the same place as the MRS and the results are generally consistent. Low resistivity layers interpreted as clay are sometimes identified close to the surface. The MRS result in site 2 is a good example of signals penetrating through the clay and deeper aquifer still being detected. The MRS data suggest aquifers that are not only hosted in soft sediment materials (moraine, sand, and mixed materials), but hosted in basement rocks. Based on the MRS and borehole pumping test data, the results agree with yield, average water content and subsurface geological data.  相似文献   

Growth of rigid high-relief patch reefs, Mid-Silurian, Gotland, Sweden   总被引：2，自引：0，他引：2  

Nigel R. Watts  & Robert Riding 《Sedimentology》2000,47(5):979-994

Patch reefs up to 35 m thick and generally 100–150 m wide, separated by bedded inter-reef sediment, dominate the Högklint Formation (Lower Wenlock) of north-west Gotland. The spacing between adjacent patch reefs is variable, but is commonly 150–350 m. The Högklint is a shallowing sequence, and the patch reefs exhibit a well-developed vertical succession: (1) Axelsro-type patch reefs developed in the underlying Visby Formation; (2) halysitid tabulates capped by laminar stromatoporoids; (3) domical and bulbous stromatoporoids and red algae; (4) cyanobacterial–algal reef crest. The patch reefs expand upwards from an initial bioherm phase with a small base to a laterally extensive biostrome phase. This gives them a thumb-tack appearance. In stage 2 of the bioherm phase, rigid framework development and high reef relief resulted in breakage of angular blocks up to 15 m long, which were incorporated into the reefs or fell into adjacent sediments. Poorly sorted talus haloes (Millingsklint Member) also developed adjacent to stage 2 of the bioherm phase. These include angular blocks and exhibit depositional slopes up to 40° away from the reefs. Stage 3 biostrome development was mainly non-rigid cluster reef, which shed skeletal debris (Domkyrka Member) but few lithified blocks. Stage 4 biostrome development was a reef crest with open to closed frame structure. Storm breakage and overturning produced large blocks with complex cavity fill sequences including double geopetals. Relief during the bioherm phase, indicated by fallen blocks and talus slopes, was up to at least 15 m; during the biostrome phase, it was up to 10 m.  相似文献   

Climate and environment during the Younger Dryas (GS‐1) as reflected by composite stable isotope records of lacustrine carbonates at Torreberga,southern Sweden     

Dan Hammarlund  Thomas W. D. Edwards  Svante Bjrck  Bjrn Buchardt  Barbara Wohlfarth 《第四纪科学杂志》1999,14(1):17-28

Climatic and environmental changes during the Younger Dryas stadial (GS‐1) and preceding and following transitions are inferred from stable carbon and oxygen isotope records obtained from the sediments of ancient Lake Torreberga, southern Sweden. Event GS‐1 is represented in the sediment sequence by 3.5 m of clay containing lacustrine carbonates of various origins. Comparison of isotopic records obtained on mollusc shells, ostracod valves, and Chara encrustations precipitated during specific seasons of the year supports estimates of relative changes in both lake water and mean annual air temperatures. Variations in soil erosion rates can also be estimated from a simple isotope–mass‐balance model to separate allochthonous and autochthonous carbonate contributions to the bulk carbonate content of the sediments. The well‐known, rapid climatic shifts characterising the Last Termination in the North Atlantic region are clearly reflected in the isotopic data, as well as longer‐term changes within GS‐1. Following maximum cooling shortly after the Allerød–Younger Dryas (GI‐1–GS‐1) transition, a progressive warming and a slight increase in aquatic productivity is indicated. At the Younger Dryas–Preboreal (GS‐1–PB) transition mean annual air temperature rapidly increased by more than 5°C and summer lake‐water temperature increased by ca. 12°C. The subsequent Preboreal oscillation is characterised by an increase in soil erosion and a slight decrease in mean annual air temperature. These results are in harmony with recent findings about large‐scale climate dynamics during the Last Termination. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

Early Holocene dune field development in Dalarna,central Sweden: A geomorphological and geophysical case study          下载免费PDF全文

Martin Bernhardson  Helena Alexanderson 《地球表面变化过程与地形》2017,42(12):1847-1859

Bonäsheden, Sweden's largest continuous dune field, situated in the county of Dalarna, central Sweden, has been investigated using LiDAR (light detection and ranging) remote sensing, ground penetrating radar as well as by field observations and luminescence dating. The use of LiDAR in conjunction with geographic information system (GIS) software proved to be efficient in mapping the inactive dune field and classifying the dune morphology, especially when slope raster images were used. The dunes have formed mostly by winds from the northwest (NW) and are of a transverse type. Still other dune types, such as parabolic dunes, and transverse dunes with a deviating orientation are present. Also, there seems to be different generations of dunes, suggesting a complex palaeowind environment with a change from predominantly north‐westerly winds to more westerly winds. Luminescence dating finally allows us to have an absolute chronology of the development of the Bonäsheden dune field, revealing formation of the dune field closely following the de‐glaciation of this part of Sweden (c. 10.5 ka). The well preserved transverse shape of the majority of the dunes suggests rapid stabilization by vegetation, although sand drift still seems to have been active on a noticeable scale for at least 1500 years and also, occasionally and patchy, as coversand deposition during the Late Holocene. A simple model is proposed for the dune field development of Bonäsheden based on our findings. This model is a useful addition since the majority of present day dune field models focus on the formation of parabolic dunes or large unvegetated dune fields. Our results suggest that most models cannot adequately simulate the formation of such small dune fields as that of Bonäsheden, with apparently rapidly fixated transverse dunes in a previously glaciated, now vegetated area. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

Artificial reef effect and fouling impacts on offshore wave power foundations and buoys – a pilot study     

Olivia Langhamer  Dan Wilhelmsson  Jens Engström 《Estuarine, Coastal and Shelf Science》2009

Little is known about the effects of offshore energy installations on the marine environment, and further research could assist in minimizing environmental risks as well as in enhancing potential positive effects on the marine environment. While biofouling on marine energy conversion devices on one hand has the potential to be an engineering concern, these structures can also affect biodiversity by functioning as artificial reefs. The Lysekil Project is a test park for wave power located at the Swedish west coast. Here, buoys acting as point absorbers on the surface are connected to generators anchored on concrete foundations on the seabed. In this study we investigated the colonisation of foundations by invertebrates and fish, as well as fouling assemblages on buoys. We examined the influence of surface orientation of the wave power foundations on epibenthic colonisation, and made observations of habitat use by fish and crustaceans during three years of submergence. We also examined fouling assemblages on buoys and calculated the effects of biofouling on the energy absorption of the wave power buoys. On foundations we demonstrated a succession in colonisation over time with a higher degree of coverage on vertical surfaces. Buoys were dominated by the blue mussel Mytilus edulis. Calculations indicated that biofouling have no significant effect in the energy absorption on a buoy working as a point absorber. This study is the first structured investigation on marine organisms associated with wave power devices.  相似文献   

Spatial patterns in community structure of motile epibenthic fauna in coastal habitats along the Skagerrak – Baltic salinity gradient     

Emma Nohrén  Leif Pihl  Håkan Wennhage 《Estuarine, Coastal and Shelf Science》2009

Patterns in community structure and functioning of motile epibenthic fauna were investigated in shallow (0–1 m) sediment habitats along the Skagerrak–Baltic estuarine gradient (salinity range from 4 to 34). The study area was divided into five regions, reflecting different sea-basins along the 1260 km coastline, and fauna was collected at six sites within each region. Ten replicate samples of motile epibenthic fauna were taken randomly at each site with a portable drop trap (bottom area 1 m²) in June and September in 2004.  相似文献   

Beyond “Guggenheiming”: From flagship buildings to flagship space in Sweden     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):228-237

Flagship buildings are promoted as a good strategy to stimulate economic development. Pushed by a range of actors, “best practice” examples are being copied from place to place around the globe. Flagship buildings are accompanied by a discourse of place branding that stresses a need for cities to improve their attractiveness. Drawing on this discourse and ongoing discussions on deterritorialization and reterritorialization in urban and economic geography, the author argues that there is an overly deterritorialized approach to flagship buildings in the place-branding literature. Using a conceptual framework inspired by the reterritorialization debate, she introduces the concept of “flagship space,” emphasizing a dualism in place branding encompassing both deterritorialized and territorial processes that in interplay create best-practice examples. The empirical analysis examines the development of five flagship hotels in Sweden. The author concludes that the five hotels have both created and are constantly reproducing their statuses as flagship developments. However, the creation and reproduction of status is not only upheld by the operators of the hotels but is also a joint effort of actors in the local community. Through these processes and practices the understanding of the hotels is broadened from merely being flagship buildings to creators of flagship space.  相似文献   

Taphonomy and palaeoecology of the gastropod fauna from a Late Cretaceous rocky shore, Sweden     

Anne Mehlin Sørensen Finn Surlyk 《Cretaceous Research》2011,32(4):472-479

A gastropod fauna comprising 17 species, each represented by a limited number of specimens, is described from a Late Cretaceous, late early Campanian rocky shore at Ivö Klack, southern Sweden. The gastropod fauna is associated with the most diverse ancient rocky shore fauna ever found. However, the low gastropod species diversity compared to the faunas of modern rocky shores is ascribed to taphonomic factors, notably dissolution of the aragonitic shells, but the predominance of epifaunal herbivores is indicative of a guild structure similar to that found on modern rocky shores. The presence of drill holes assigned to the ichnospecies Oichnus simplex suggests the former presence of muricid gastropods which have not been found as body fossils. A single drill hole is referred to Oichnus paraboloides and was probably made by a naticid gastropod. The infaunal mode of life of naticids makes preservation of such drill holes difficult, since the majority of infaunal prey such as burrowing bivalves has aragonitic shells which are not preserved. The relatively high number of species in comparison to many other Late Cretaceous rocky shore faunas, offers an opportunity to compare gastropod guild structure at Ivö Klack with modern counterparts, even though taphonomic processes such as mechanical destruction and aragonite dissolution have played an important role in the fossil gastropod assemblage.  相似文献   

Tectonothermal evolution of high-alumina rocks within the Protogine Zone, southern Sweden   总被引：2，自引：0，他引：2  

P. G. ANDRÉASSON  R. D. DALLMEYER 《Journal of Metamorphic Geology》1995,13(4):461-474

Abstract The Protogine Zone comprises a system of anastomosing deformation zones which approximately parallel the eastern boundary of the Sveconorwegian (1200–900 Ma) province in south-west Sweden. Ages of granulite facies metamorphism in the Sveconorwegian province require exhumation from c . 30 to 35 km crustal depths after 920–880 Ma. ⁴⁰Ar/³⁹ Ar cooling ages are presented for muscovite from high-alumina rocks formed by hydrothermal leaching associated with the Protogine Zone. Growth of fabric-defining minerals was associated with a ductile deformational event; muscovite from these rocks cooled below argon retention temperatures ( c . 375 ± 25° C) at c . 965–955 Ma. Muscovite from granofels in zones of intense alteration indicates that temperatures > 375 ± 25° C were maintained until c . 940 Ma. Textural relations of Al₂SiO₅ polymorphs and chloritoid suggest that dated fabrics formed during exhumation. The process of exhumation, brittle overprint on ductile structures and hydrothermal activity along faults within the Protogine Zone tentatively are interpreted as the peripheral effects of initial Neoproterozoic exhumation of the granulite region of south-western Sweden.
Muscovite in phyllonites associated with the 'Sveconorwegian thrust system'cooled below argon retention temperatures at c . 927 Ma. Exhumation associated with this cooling could have been related to extension and onset of brittle-ductile deformation superimposed on Sveconorwegian contraction.  相似文献   

Maximum Likelihood Estimation of Seismic Hazard for Sweden     

Andrzej Kijko  Efthimios Skordas  Rutger Wahlström  Päivi Mäntyniemi 《Natural Hazards》1993,7(1):41-57

The maximum magnitude, the activity rate, and the Gutenberg-Richterb parameter as earthquake hazard parameters, have been evaluated for Sweden. The maximum likelihood method permits the combination of historical and instrumental data. The catalog used consists of 1100 earthquakes in the time interval 1375–1989. The extreme part of the catalog contains only the strongest historical earthquakes, whereas the complete part is divided into several subcatalogs, each assumed complete above a specified threshold magnitude. The uncertainty in magnitude determination was taken into account. For southern Sweden, the calculations giveb-values of 1.04 (0.05) for the whole area south of 60° N and 0.98 (0.06) for a subregion of enhanced seismicity in the Lake Vänern area. For the whole area north of 60° N, theb-value is 1.35 (0.06) and for the seismicity zone along the Gulf of Bothnia 1.26 (0.06). The number of annually expected earthquakes with magnitude equal to or larger than 2.4 [M_L(UPP) or M_M(UPP)] is 1.8 for the whole southern Sweden, 1.3 for the Lake Vänern region, 3.7 for northern Sweden, and 2.4 for the region along the Gulf of Bothnia. The maximum expected regional magnitude is calculated to 4.9 (0.5) for a time span of 615 years for southern Sweden and the Lake Vänern subregion, and 4.3 (0.5) for a time span of 331 years for northern Sweden and the Gulf of Bothnia subregion. However, several historical earthquakes with magnitude above 5 in nearby areas of Norway indicate that the seismic potential may be higher.  相似文献