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51.
Nathan S. Hall R. Wayne Litaker Elizabeth Fensin Jason E. Adolf Holly A. Bowers Allen R. Place Hans W. Paerl 《Estuaries and Coasts》2008,31(2):402-418
A dense bloom of the ichthyotoxic dinoflagellate Karlodinium veneficum was discovered in the Neuse River Estuary, North Carolina, on 19 October 2006 and was associated with four subsequent fish
kills. Microscopic, photopigment, DNA, and toxicological techniques confirmed bloom identity and toxicity. High-resolution
spatio-temporal data from ship-board and fixed automated sampling stations provided a unique opportunity to investigate the
environmental conditions that initiated, maintained, and terminated the K. veneficum bloom. Bloom initiation and growth were favored by high nutrient availability and reduced dispersal during the period of
declining riverine discharge after Tropical Storm Ernesto. K. veneficum out-competed other co-occurring dinoflagellates, perhaps because of the production of karlotoxins that are known to act as
grazing deterrents and to facilitate mixotrophic feeding. Once the bloom was established, small-scale hydrodynamic processes,
coupled with vertical migration, concentrated cells along a frontal convergence to high densities (>200,000 cells per milliliter).
By 26 October 2006, wind mixing and possible nutrient stress disrupted the bloom. Release of cell-bound toxins during the
bloom collapse likely accounted for the associated fish kill events where fish were reported as exhibiting typical symptoms
of karlotoxin poisoning. The dynamics of this bloom underscore the tight control of harmful algal blooms by meteorological
forcing, hydrology, and sediment nutrient input in this shallow lagoonal estuary. 相似文献
52.
A coupled model, consisting of an ocean wave model and an atmospheric general circulation model (AGCM), is integrated under permanent July conditions. The wave model is forced by the AGCM wind stress, whereas the wind waves modify the AGCM surface fluxes of momentum, sensible and latent heat. We investigate the following aspects of the coupled model: how realistic are the wave fields, how strong is the coupling, and how sensitive is the atmospheric circulation to the spatially and temporally varying wave field. The wave climatology of the coupled model compares favorably with observational data. The interaction between the two models is largest (although weak) in the storm track in the Southern Hemisphere. Young windsea, which is associated with enhanced surface fluxes is generated mostly in the equatorward frontal area of an individual cyclone. However, the enhancement of the surface fluxes is too small to significantly modify the climatological mean atmospheric circulation.This paper was presented at the Second International Conference on Modelling of Global Climate Variability, held in Hamburg 7–11 September 1992 under the auspices of the Max Planck Institute for Meteorology. Guest Editor for these papers is L. Dümenil 相似文献
53.
Sumba island forms part of a continental fragment, located near the transition of the Sunda Arc to the Banda Arc. It lies within the forearc region, between the active volcanic arc to the north and the Java Trench to the south. Palaeomagnetic studies of Cretaceous (late Albian-early Campanian) Lasipu sediments revealed a mean characteristic remanence (ChRM) direction with D = 42.5°, I = –23.0° and _95 = 6.1°, indicating a palaeolatitude of 12° S. This ChRM is, most likely, a secondary magnetization, possibly caused by the intrusion of the 65-Ma-old Tanadaro granodiorite. This granodiorite gave a mean ChRM direction with D = 44.7°, I = –16.3°, and 95 = 12.2°, pointing to a palaeolatitude of 8.3° S. Eastern Sundaland with Borneo, west and south Sulawesi, and Sumba formed one continental unit in the late Mesozoic, most likely attached to the southeast Asian mainland. Borneo and west and south Sulawesi underwent large counterclockwise (CCW) rotations since the Jurassic with 45° during the Cretaceous, and 45° during the Palaeogene. The Sumba microcontinent, most likely, became detached from eastern Sundaland soon after deposition of the Lasipu sediments. Palaeomagnetic data show that Sumba underwent subsequent clockwise (CW) rotations of up to 96°: 53° between 82 and 65 Ma, and 38° between 65 and 37 Ma. Since the late Eocene, only small rotations occurred. The data indicate that eastern Sundaland, including Sumba, remained close to the equator since the Jurassic. CW rotations occurred in Sundaland both in the north (Indochina) and in the west (Sibumasu) as a consequence of the India – Eurasia collision. The same sense of rotation is seen further east in Sulawesis East Arm and the Philippine Sea plate. Eastern Sundaland (Borneo and west Sulawesi) with CCW rotations is being trapped between these CW rotating plates. 相似文献
54.
The Menilite Shales (Oligocene) of the Polish Carpathians are the source of low-sulfur oils in the thrust belt and some high-sulfur oils in the Carpathian Foredeep. These oil occurrences indicate that the high-sulfur oils in the Foredeep were generated and expelled before major thrusting and the low-sulfur oils in the thrust belt were generated and expelled during or after major thrusting. Two distinct organic facies have been observed in the Menilite Shales. One organic facies has a high clastic sediment input and contains Type-II kerogen. The other organic facies has a lower clastic sediment input and contains Type-IIS kerogen. Representative samples of both organic facies were used to determine kinetic parameters for immiscible oil generation by isothermal hydrous pyrolysis and S2 generation by non-isothermal open-system pyrolysis. The derived kinetic parameters showed that timing of S2 generation was not as different between the Type-IIS and -II kerogen based on open-system pyrolysis as compared with immiscible oil generation based on hydrous pyrolysis. Applying these kinetic parameters to a burial history in the Skole unit showed that some expelled oil would have been generated from the organic facies with Type-IIS kerogen before major thrusting with the hydrous-pyrolysis kinetic parameters but not with the open-system pyrolysis kinetic parameters. The inability of open-system pyrolysis to determine earlier petroleum generation from Type-IIS kerogen is attributed to the large polar-rich bitumen component in S2 generation, rapid loss of sulfur free-radical initiators in the open system, and diminished radical selectivity and rate constant differences at higher temperatures. Hydrous-pyrolysis kinetic parameters are determined in the presence of water at lower temperatures in a closed system, which allows differentiation of bitumen and oil generation, interaction of free-radical initiators, greater radical selectivity, and more distinguishable rate constants as would occur during natural maturation. Kinetic parameters derived from hydrous pyrolysis show good correlations with one another (compensation effect) and kerogen organic-sulfur contents. These correlations allow for indirect determination of hydrous-pyrolysis kinetic parameters on the basis of the organic-sulfur mole fraction of an immature Type-II or -IIS kerogen. 相似文献
55.
Hans Knippenberg 《GeoJournal》2006,67(4):253-265
Historical processes of state formation and nation building are crucial for an understanding of the geography of religions
and churches in Europe. Each country has developed its own model of state-church relations, giving rise to a ‘bewildering
variety’ as Grace Davie aptly remarks. The aim of this paper is to bring some order to this variety by developing a framework
for the comparative study of church-state relations based on Stein Rokkan’s famous conceptual map and recent extensions of
it to Central and Eastern Europe by John Madeley. According to that framework Europe has been divided into three mono-confessional
(Roman Catholic, Lutheran, and Eastern Orthodox) blocs and two multi-confessional culture belts from Northwest to Southeast,
and from Northeast to Southeast. This historical pattern has been challenged by secularisation, which started with the Enlightenment
and the French Revolution (Western Europe) and the Russian Revolution (Eastern Europe until the velvet revolutions of 1989/1991)
and then became widespread after the ‘cultural revolutions’ of the 1960s. A second challenge has to do with globalisation
and its consequences, such as massive immigration and the rise of immigrant religions, and in general deterritorialisation,
which means the disembeddedness of religion from its national territory. A third challenge concerns reterritorialisation at
other (supranational, regional, transnational, and local) scales, of which the new territorial order of the European Union
seems to be the most important. Finally, this paper serves as an introduction to the case studies on church-state relations
in this special issue. 相似文献
56.
Histograms of observations from spatial phenomena are often found to be more heavy-tailed than Gaussian distributions, which
makes the Gaussian random field model unsuited. A T-distributed random field model with heavy-tailed marginal probability density functions is defined. The model is a generalization
of the familiar Student-T distribution, and it may be given a Bayesian interpretation. The increased variability appears cross-realizations, contrary
to in-realizations, since all realizations are Gaussian-like with varying variance between realizations. The T-distributed random field model is analytically tractable and the conditional model is developed, which provides algorithms
for conditional simulation and prediction, so-called T-kriging. The model compares favourably with most previously defined random field models. The Gaussian random field model
appears as a special, limiting case of the T-distributed random field model. The model is particularly useful whenever multiple, sparsely sampled realizations of the
random field are available, and is clearly favourable to the Gaussian model in this case. The properties of the T-distributed random field model is demonstrated on well log observations from the Gullfaks field in the North Sea. The predictions
correspond to traditional kriging predictions, while the associated prediction variances are more representative, as they
are layer specific and include uncertainty caused by using variance estimates. 相似文献
57.
K. W. Helen Lau Keith E. Louden Sharon Deemer Jeremy Hall John R. Hopper Brian E. Tucholke W. Steven Holbrook Hans Christian Larsen † 《Geophysical Journal International》2006,167(1):157-170
New multichannel seismic reflection data were collected over a 565 km transect covering the non-volcanic rifted margin of the central eastern Grand Banks and the Newfoundland Basin in the northwestern Atlantic. Three major crustal zones are interpreted from west to east over the seaward 350 km of the profile: (1) continental crust; (2) transitional basement and (3) oceanic crust. Continental crust thins over a wide zone (∼160 km) by forming a large rift basin (Carson Basin) and seaward fault block, together with a series of smaller fault blocks eastwards beneath the Salar and Newfoundland basins. Analysis of selected previous reflection profiles (Lithoprobe 85-4, 85-2 and Conrad NB-1) indicates that prominent landward-dipping reflections observed under the continental slope are a regional phenomenon. They define the landward edge of a deep serpentinized mantle layer, which underlies both extended continental crust and transitional basement. The 80-km-wide transitional basement is defined landwards by a basement high that may consist of serpentinized peridotite and seawards by a pair of basement highs of unknown crustal origin. Flat and unreflective transitional basement most likely is exhumed, serpentinized mantle, although our results do not exclude the possibility of anomalously thinned oceanic crust. A Moho reflection below interpreted oceanic crust is first observed landwards of magnetic anomaly M4, 230 km from the shelf break. Extrapolation of ages from chron M0 to the edge of interpreted oceanic crust suggests that the onset of seafloor spreading was ∼138 Ma (Valanginian) in the south (southern Newfoundland Basin) to ∼125 Ma (Barremian–Aptian boundary) in the north (Flemish Cap), comparable to those proposed for the conjugate margins. 相似文献
58.
59.
Hans Knippenberg 《GeoJournal》2006,67(4):317-330
The Netherlands is part of the historic Northwest-Southeast multi-confessional culture belt according to the comparative framework
of church-state relations in Europe as recently developed by Madeley on the basis of Rokkan’s conceptual map. The aim of this
paper is to describe the development of the church-state relations in the Netherlands within this historic framework of state-formation
and nation-building, and to interpret recent challenges of its historic state-church model, such as secularisation, the rise
of immigrant religions, and general ‘de- and re-territorialisation’ tendencies. The Netherlands developed from a relatively
very tolerant polity dominated by the Calvinist Church to a ‘pillarised’ society, in which the Rome-Reformation divide (which
also had a strong geographical dimension) was institutionalised in the political system. After the 1960s, very strong secularisation
put this ‘pillarised’ system under severe pressure, but the remnants of this system offered a favourable opportunity structure
for religious newcomers (Muslims in particular), who could establish their mosques and Muslim schools relatively easily. However,
while the main Protestant churches, and even Catholic and Protestant political parties have merged, failing integration of
these newcomers in Dutch society and terrorist attacks at the global level as well as in the Netherlands encouraged a new
divide between Muslims and non-Muslims. The metropolitan areas in particular became the scene of this new divide. 相似文献
60.
韧性剪切变形对岩石地球化学行为的制约——以北阿尔金巴什考供韧性剪切带为例 总被引:6,自引:0,他引:6
韧性剪切变形对岩石地球化学行为的制约一直是地质学家们探讨的课题。本文以构成北阿尔金红柳沟——拉配泉俯冲碰撞杂岩带与北阿尔金地块边界的巴什考供斜向逆冲型韧性剪切带为例,通过对韧性剪切带内花岗岩变形前后不同变形强度构造岩的地球化学组成进行对比,确定等比线斜率,探讨韧性变形对岩石体积和成分变异的影响。计算结果表明,在糜棱岩化过程中,糜棱岩化花岗岩体积亏损21%,花岗质糜棱岩体积亏损31%。质量平衡计算结果和等比线图表明,韧;陛剪切作用导致SiO2,流失量最大,A12O3、K2O及Ba、Rb、Sr等都有不同程度的丢失,显示出较强的活动性,MnO、P2O5、Sc位于等比线上或附近,表现出相对的稳定性。岩石中活动组分的变异是流体渗滤作用引起的,不活动组分的变异是体.积亏损造成的。 相似文献