Faults in crystalline rock and the estimation of their mechanical properties at the Olkiluoto site,western Finland     

John A. Hudson  John W. Cosgrove  Kimmo Kemppainen  Erik Johansson 《Engineering Geology》2011,117(3-4):246-258

Brittle deformation zones at the Olkiluoto nuclear repository site in western Finland play critical roles in the strength and hydrology of the host rock mass. We present a procedure implemented there for incorporating information on deformation zones obtained through boreholes into quantitative engineering design. First, ductile and brittle deformation zones are classified based on their characteristics in drillhole cores as brittle joint clusters, brittle fault zones, or semi-brittle fault zones, with an awareness of the geologic processes that caused the zones to develop as they did. Next, it is shown that the mechanical properties of the brittle deformation zones can be calculated by one of several methods, each of which has advantages and disadvantages. The site geology must be kept in mind at all stages to arrive at meaningful estimates of the mechanical properties of the deformation zones.  相似文献   

Emission metrics under the 2 °C climate stabilization target     

Katsumasa Tanaka  Daniel J. A. Johansson  Brian C. O’Neill  Jan S. Fuglestvedt 《Climatic change》2013,117(4):933-941

In multi-gas climate policies such as the Kyoto Protocol one has to decide how to compare the emissions of different greenhouse gases. The choice of metric could have significant implications for mitigation priorities considered under the prospective negotiations for climate mitigation agreements. Several metrics have been proposed for this task with the Global Warming Potential (GWP) being the most common. However, these metrics have not been systematically compared to each other in the context of the 2 °C climate stabilization target. Based on a single unified modeling framework, we demonstrate that metric values span a wide range, depending on the metric structure and the treatment of the time dimension. Our finding confirms the basic salient point that metrics designed to represent different aspects of the climate and socio-economic system behave differently. Our result also reflects a complex interface between science and policy surrounding metrics. Thus, it is important to select or design a metric suitable for climate stabilization based on an interaction among practitioners, policymakers, and scientists.  相似文献   

Recent advances on study of hadrosaurid dinosaurs in Heilongjiang(Amur) River area between China and Russia          下载免费PDF全文

Pascal Godefroit  Pascaline Lauters  Jimmy Van Itterbeeck  Yuri L. Bolotsky  Ivan Y. Bolotsky 《世界地质(英文版)》2011,(3):160-191

Four main dinosaur-bearing sites have been investigated in latest Cretaceous deposits from the Amur/Heilongjiang Region: Jiayin and Wulaga in China (Yuliangze Formation) ,Blagoveschensk and Kundur in Rus- sia (Udurchukan Formation) . More than 90% of the bones discovered in these localities belong to hollowcrested lambeosaurine hadrosaurids: Charonosaurus jiayinensis at Jiayin,Amurosaurus riabinini at Blagoveschensk, Olorotitan arharensis at Kundur,and Sahaliyania elunchunorum at Wulaga. Flat-headed hadrosaurine hadrosau- rids are much less numerous,but appear well diversified as well: Kerberosaurus manakini at Blagoveschensk, Wulagasaurus dongi at Wulaga,and a new genus at Kundur. Theropods are represented by shed teeth and isolated bones; isolated scutes and teeth discovered at Kundur are tentatively attributed to nodosaurids. Palynologi- cal studies suggest that these sites are probably synchronous with the Lancian’ vertebrate localities of western North America,which represent the youngest dinosaur faunas in this area. However,the latest Cretaceous dinosaur assemblages are completely different in the Amur/Heilongjiang region (lambeosaurines abundant,ceratopsids absent) and in western North America (ceratopsids abundant,lambeosaurines extremely rare or absent) . This probably reflects some kind of geographical barrier between both areas by Maastrichtian time rather than strong differences in palaeoecological conditions.  相似文献   

Low-mass star formation in Lynds 1333     

M. Kun  S. Nikoli&#;  L. E. B. Johansson  Z. Balog †  A. Gáspár 《Monthly notices of the Royal Astronomical Society》2006,371(2):732-738

  相似文献   

Analysis of rainfall and temperature time series to detect long-term climatic trends and variability over semi-arid Botswana     

Jimmy Byakatonda  B P Parida  Piet K Kenabatho  D B Moalafhi 《Journal of Earth System Science》2018,127(2):25

Arid and semi-arid environments have been identified with locations prone to impacts of climate variability and change. Investigating long-term trends is one way of tracing climate change impacts. This study investigates variability through annual and seasonal meteorological time series. Possible inhomogeneities and years of intervention are analysed using four absolute homogeneity tests. Trends in the climatic variables were determined using Mann–Kendall and Sen’s Slope estimator statistics. Association of El Niño Southern Oscillation (ENSO) with local climate is also investigated through multivariate analysis. Results from the study show that rainfall time series are fully homogeneous with 78.6 and 50% of the stations for maximum and minimum temperature, respectively, showing homogeneity. Trends also indicate a general decrease of 5.8, 7.4 and 18.1% in annual, summer and winter rainfall, respectively. Warming trends are observed in annual and winter temperature at 0.3 and 1.5% for maximum temperature and 1.7 and 6.5% for minimum temperature, respectively. Rainfall reported a positive correlation with Southern Oscillation Index (SOI) and at the same time negative association with Sea Surface Temperatures (SSTs). Strong relationships between SSTs and maximum temperature are observed during the El Niño and La Niña years. These study findings could facilitate planning and management of agricultural and water resources in Botswana.  相似文献   

Human damage assessments of coastal flooding for Hong Kong and the Pearl River Delta due to climate change-related sea level rise in the twenty-first century     

Yu  Qiwei  Lau  Alexis K. H.  Tsang  Kang T.  Fung  Jimmy C. H. 《Natural Hazards》2018,92(2):1011-1038

Natural Hazards - The adverse impact of climate change-associated extreme weather events is becoming more significant globally, particularly the flood impact on coastal and low-lying areas such as...  相似文献   

Tidal Fluctuation Influenced Physicochemical Parameter Dynamics in Coastal Groundwater Mixing Zone   总被引：1，自引：0，他引：1  

Yi Liu  Jiu Jimmy Jiao  Wenzhao Liang 《Estuaries and Coasts》2018,41(4):988-1001

Tidal fluctuation could modify the physicochemical parameters in coastal groundwater mixing zone (CGMZ) notably, which in turn largely impacts on the reactive transport, discharge, and cycling of carbon, nutrients, trace metals, and other dissolved constituents. In this study, to capture the dynamic of groundwater physicochemical parameters (e.g., salinity, dissolved oxygen, pH, temperature, and oxidation/reduction potential) under the effect of tidal fluctuation, in situ measurement of groundwater is conducted along a 2D transection at different tidal stages. The results demonstrate visible periodic variations of parameters like salinity, temperature, DO, and pH, while the groundwater pH oscillation displays a phase lag behind the tidal fluctuation. Furthermore, the salinity variation at the near-surface area is mainly controlled by the mixing process between the infiltrated seawater and groundwater. Barring the mixing process, the groundwater temperature at the near-surface area is also affected by day and night air temperature difference. Meanwhile, the depleting DO and declining pH indicate that the biodegradation via aerobic respiration is highly active in CGMZ and acts as one of the major impact factors for the DO dynamic. The sharp contrast between the high removal rate of DO (7.25 mmol m^?3 day^?1) and relatively low production rate of H⁺ (9.38 μmol m^?3 day^?1) demonstrates the existence of the processes consuming H⁺ and DO besides aerobic respiration such as dissolution of carbonates, and respiration of microorganism and mangrove roots. Moreover, owing to the mixing process, the salinity transition zone overlaps with the oxidization/reduction potential transition zone. The enrichment of Fe²⁺ and Mn²⁺ could well explain the highly reducing saline groundwater observed in this study. In a nutshell, all physicochemical parameters are sensitive to tidal fluctuation, which provides implication for further study on the variation of biogeochemical process in CGMZ.  相似文献   

Character and origin of variably deformed granitoids in central southern Sweden: implications from geochemistry and Nd isotopes     

Karin Appelquist  Linus Brander  ke Johansson  Ulf Bertil Andersson  David Cornell 《Geological Journal》2011,46(6):597-618

We present major and trace element data for eighteen 1.71–1.66 Ga granitoid samples, and Sm–Nd whole‐rock isotope data for eleven of these samples, in a transect across the border between the Transscandinavian Igneous Belt (TIB) and the Eastern Segment in central southern Sweden. The geochemistry of the granitoids varies from alkalic to alkali‐calcic and peraluminous in the east to predominantly calc‐alkaline and metaluminous in the west. Rocks in the west also have lower SiO₂ contents. Trace element signatures favour formation in an active continental margin setting. Nd isotope data are completely overlapping along the transect and initial ε_Nd values are mildly depleted in the range +0.3 to +2.6. The combined data suggest that the magmas were derived mainly from juvenile, pre‐existing crust, increasingly mafic and less alkaline towards the west. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Community structure in boreal lakes with recurring blooms of the nuisance flagellate Gonyostomum semen     

Karin S. L. Johansson  Cristina Trigal  Tobias Vrede  Richard K. Johnson 《Aquatic Sciences - Research Across Boundaries》2013,75(3):447-455

Blooms of the nontoxic raphidophyte Gonyostomum semen have shown a recent increase in frequency and distribution in the Fennoscandian region. Due to large cell size and several grazer-avoidance strategies, G. semen is hypothesized to be inedible for most zooplankton species and therefore may constitute a bottleneck for the transfer of energy and nutrients in pelagic food webs. Repression of other phytoplankton through increased competition and induced mortality could further exacerbate this effect. In a field study of four lakes with recurring blooms of G. semen and four lakes without blooms, we found significant differences in community structure between the two lake groups during the bloom period. Bloom-lakes had lower biovolumes of small chrysophytes and chlorophytes and zooplankton assemblages were predominated by small, potentially bacterivorous cladocerans, suggesting a limited availability of edible phytoplankton and an increased importance of microbial pathways during G. semen blooms. Low biovolumes of large cladocerans in bloom-lakes may be due to interference of G. semen with filter feeding. Moreover, high abundances of the phantom midge Chaoborus flavicans in bloom-lakes suggest that the flow of energy and nutrients is directed more towards this invertebrate predator than fish. This could have negative impacts on fish populations, especially if bloom periods are prolonged.  相似文献   

Beyond the Metropolis: Urban Geography as if Small Cities Mattered     

Ola Johansson 《The Professional geographer》2013,65(3):430-432

In-car satellite navigation systems (SatNavs) are among the first products based on geographic information systems to have widespread fashionable appeal. In the United Kingdom, portable versions that are easily installed on the dashboard or front windshield have become a popular vehicle accessory. As prices have fallen, demand has increased over the last few years to the point that SatNavs might soon achieve the ubiquity of in-car entertainment systems. The rise of popularity of SatNavs, however, has also brought with it increased vulnerability to vehicle crime. Our analysis for the London borough of Newham shows a threefold increase in SatNav theft that occurred from 2005–2006 to 2006–2007. This is not limited to SatNavs being on display, but criminals also looking for the telltale signs of suction marks on the windshield indicating that a portable SatNav might be in the glove compartment or trunk of the car. A geographical analysis of these crime data is presented. Whereas the geo-engineering has focused on improving real-time visualization of position and articulation of navigational instructions, the product engineering as a portable accessory has insufficiently addressed the social implications of vulnerability in a high-crime society, the consequence being a focused acquisitive crime wave.  相似文献