Monitoring biological effects of pollution in the Baltic Sea: neglected--but still wanted?     

Lehtonen KK  Schiedek D 《Marine pollution bulletin》2006,53(8-9):377-386

In the Baltic Sea, studies regarding biological effects of contaminants are relatively few, partly due to political and economical reasons, specific hydrographic characteristics, and a strong eutrophication-targeted research focus during the past three decades. The development of a monitoring strategy concerning biological effects and its implementation into environmental monitoring programmes in the Baltic Sea is lagging behind the progress currently taking place in most of western and southern Europe. The pan-European project BEEP (Biological Effects of Environmental Pollution on Marine Coastal Ecosystems, 2001-2004) included the Baltic Sea as one of the target areas for the evaluation of a suite of biological effects indicators in European coastal waters. The main aims of the BEEP project are described and how the expected outcome for the Baltic Sea could provide the needed "baseline" information and expertise for a biological effect monitoring and contribute to harmonise environmental monitoring programmes within the EU.  相似文献   

Biochemical biomarkers in adult female perch (Perca fluviatilis) in a chronically polluted gradient in the Stockholm recipient (Sweden)     

Hansson T  Schiedek D  Lehtonen KK  Vuorinen PJ  Liewenborg B  Noaksson E  Tjärnlund U  Hanson M  Balk L 《Marine pollution bulletin》2006,53(8-9):451-468

A battery of biochemical biomarkers and the SigmaPCB concentration in adult female perch (Perca fluviatilis) verified an aquatic pollution gradient with the city of Stockholm (Sweden) as a point source of anthropogenic substances. The investigation included both an upstream gradient, 46 km westwards through Lake M?laren, and a downstream gradient, 84 km eastwards through the Stockholm archipelago. Besides the main gradient from Stockholm, there were strong indications of pollution coming from the Baltic Sea. The results indicated a severe pollution situation in central Stockholm, with poor health status of the perch, characterised by increased specific EROD activity in the liver, increased liver EROD somatic index, decreased AChE activity in the muscle, increased amount of DNA adducts in the liver, and a high concentration of biliary 1-pyrenol. In addition, laboratory exposure to common EROD inducers elicited an abnormal response, suggestive of chronic intoxication.  相似文献   

Palaeomagnetic cave stratigraphy of sediments from Hellemofjord, northern Norway     

Reidar Løvlie  Kari Lise Ellingsen  Stein-Erik Lauritzen 《Geophysical Journal International》1995,120(2):499-515

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Magma mixing and the generation of isotopically juvenile silicic magma at Yellowstone caldera inferred from coupling 238U–230Th ages with trace elements and Hf and O isotopes in zircon and Pb isotopes in sanidine     

Mark E. Stelten  Kari M. Cooper  Jorge A. Vazquez  Mary R. Reid  Gry H. Barfod  Josh Wimpenny  Qing-zhu Yin 《Contributions to Mineralogy and Petrology》2013,166(2):587-613

The nature of compositional heterogeneity within large silicic magma bodies has important implications for how silicic reservoirs are assembled and evolve through time. We examine compositional heterogeneity in the youngest (~170 to 70 ka) post-caldera volcanism at Yellowstone caldera, the Central Plateau Member (CPM) rhyolites, as a case study. We compare ²³⁸U–²³⁰Th age, trace-element, and Hf isotopic data from zircons, and major-element, Ba, and Pb isotopic data from sanidines hosted in two CPM rhyolites (Hayden Valley and Solfatara Plateau flows) and one extracaldera rhyolite (Gibbon River flow), all of which erupted near the caldera margin ca. 100 ka. The Hayden Valley flow hosts two zircon populations and one sanidine population that are consistent with residence in the CPM reservoir. The Gibbon River flow hosts one zircon population that is compositionally distinct from Hayden Valley flow zircons. The Solfatara Plateau flow contains multiple sanidine populations and all three zircon populations found in the Hayden Valley and Gibbon River flows, demonstrating that the Solfatara Plateau flow formed by mixing extracaldera magma with the margin of the CPM reservoir. This process highlights the dynamic nature of magmatic interactions at the margins of large silicic reservoirs. More generally, Hf isotopic data from the CPM zircons provide the first direct evidence for isotopically juvenile magmas contributing mass to the youngest post-caldera magmatic system and demonstrate that the sources contributing magma to the CPM reservoir were heterogeneous in ¹⁷⁶Hf/¹⁷⁷Hf at ca. 100 ka. Thus, the limited compositional variability of CPM glasses reflects homogenization occurring within the CPM reservoir, not a homogeneous source.  相似文献   

Recurrent transitions to Little Ice Age-like climatic regimes over the Holocene     

Helama  Samuli  Stoffel  Markus  Hall  Richard J.  Jones  Phil D.  Arppe  Laura  Matskovsky  Vladimir V.  Timonen  Mauri  N&#;jd  Pekka  Mielik&#;inen  Kari  Oinonen  Markku 《Climate Dynamics》2021,56(11):3817-3833

Holocene climate variability is punctuated by episodic climatic events such as the Little Ice Age (LIA) predating the industrial-era warming. Their dating and forcing mechanisms have however remained controversial. Even more crucially, it is uncertain whether earlier events represent climatic regimes similar to the LIA. Here we produce and analyse a new 7500-year long palaeoclimate record tailored to detect LIA-like climatic regimes from northern European tree-ring data. In addition to the actual LIA, we identify LIA-like ca. 100–800 year periods with cold temperatures combined with clear sky conditions from 540 CE, 1670 BCE, 3240 BCE and 5450 BCE onwards, these LIA-like regimes covering 20% of the study period. Consistent with climate modelling, the LIA-like regimes originate from a coupled atmosphere–ocean–sea ice North Atlantic-Arctic system and were amplified by volcanic activity (multiple eruptions closely spaced in time), tree-ring evidence pointing to similarly enhanced LIA-like regimes starting after the eruptions recorded in 1627 BCE, 536/540 CE and 1809/1815 CE. Conversely, the ongoing decline in Arctic sea-ice extent is mirrored in our data which shows reversal of the LIA-like conditions since the late nineteenth century, our record also correlating highly with the instrumentally recorded Northern Hemisphere and global temperatures over the same period. Our results bridge the gaps between low- and high-resolution, precisely dated proxies and demonstrate the efficacy of slow and fast components of the climate system to generate LIA-like climate regimes.

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On surface photometry of the moon     

Kari Lumme 《Earth, Moon, and Planets》1972,5(3-4):447-456

The surface photometric observations of the Moon made by various authors are compared with the author's theoretical scattering law (Lumme, 1971), and a good agreement is obtained. The integrated brightness of the Moon has also been calculated from these different sets of data and then compared with the observed brightness. Some differences between the different observations were found.  相似文献   

From rotations and inclinations to zero configurational velocity surfaces I. A natural rotating coordinate system     

Donald G. Saari 《Celestial Mechanics and Dynamical Astronomy》1984,33(4):299-318

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Time-course studies of the biotransformation enzymes in control rainbow trout when adjusting to new habitats     

Sirpa Huuskonen  Tiina Rsnen  Kari Koponen  Pirjo Lindstrm-Sepp 《Marine environmental research》1995,39(1-4)

Hepatic monooxygenase enzyme activities and relative cytochrome P4501A protein content were measured to evaluate the time-course alterations in rainbow trout after change in living habitat. Fish were transferred from one fish farm to the tanks of another hatchery and/or into cages kept in a lake. In the new habitats, cytochrome P450-dependent enzyme activities in rainbow trout decreased, and were at their lowest levels after two or three weeks in the summer. Later the activities partly reversed. The immunodetection of cytochrome P4501A protein expressed a similar trend as for catalytic monooxygenase activities.  相似文献   

Oxygen isotope evidence for the origin of enriched mantle beneath the mid-Atlantic ridge   总被引：1，自引：0，他引：1  

Kari M. Cooper  John M. Eiler  Paul D. Asimow  Charles H. Langmuir 《Earth and Planetary Science Letters》2004,220(3-4):297-316

Geochemical variations in mid-ocean ridge basalts have been attributed to differing proportions of compositionally distinct mantle components in their sources, some of which may be recycled crust. Oxygen isotopes are strongly fractionated by near-surface interactions of rocks with the hydrosphere, and thus provide a tracer of near-surface materials that have been recycled into the mantle. We present here oxygen isotope analyses of basaltic glasses from the mid-Atlantic ridge south of and across the Azores platform. Variations in δ¹⁸O in these samples are subtle (range of 0.47‰) and may partly reflect shallow fractional crystallization; we present a method to correct for these effects. Relatively high fractionation-corrected δ¹⁸O in these samples is associated with geochemical indices of enrichment, including high La/Sm, Ce/Pb, and ⁸⁷Sr/⁸⁶Sr and low ¹⁴³Nd/¹⁴⁴Nd. Our results suggest two first-order conclusions about these enriched materials: (1) they are derived (directly or indirectly) from recycled upper oceanic crustal rocks and/or sediments; and (2) these materials are present in the north Atlantic MORB sources in abundances of less than 10% (average 2–5%). Modeling of variations of δ¹⁸O with other geochemical variables further indicates that the enriched component is not derived from incorporation of sediment or bulk altered oceanic crust, from metasomatism of the mantle by hydrous or carbonate-rich fluids, or from partial melting of subducted sediment. Instead, the data appear to require a model in which the enriched component is depleted mantle that has been metasomatized by small-degree partial melts of subducted, dehydrated, altered oceanic crust. The age of this partial melting is broadly constrained to 250 Ma. Reconstructed plate motions suggest that the enriched component in the north Atlantic mantle may have originated by subduction along the western margin of Pangea.  相似文献   

Crustal Architecture of the Inverted Central Lapland Rift Along the HUKKA 2007 Profile     

Timo Tiira  Tomasz Janik  Elena Kozlovskaya  Marek Grad  Annakaisa Korja  Kari Komminaho  Endre HegedŰs  Csaba Attila Kovács  Hanna Silvennoinen  Ewald BrŰckl 《Pure and Applied Geophysics》2014,171(7):1129-1152

We have studied the lateral velocity variations along a partly buried inverted paleo–rift in Central Lapland, Northern Europe with a 2D wide-angle reflection and refraction experiment, HUKKA 2007. The experiment was designed to use seven chemical explosions from commercial and military sites as sources of seismic energy. The shots were recorded by 102 stations with an average spacing of 3.45 km. Two-dimensional crustal models of variations in P-wave velocity and Vp/Vs-ratio were calculated using the ray tracing forward modeling technique. The HUKKA 2007 experiment comprises a 455 km long profile that runs NNW–SSE parallel to the Kittilä Shear Zone, a major deformation zone hosting gold deposits in the area. The profile crosses Paleoproterozoic and reactivated Archean terranes of Central Lapland. The velocity model shows a significant difference in crustal velocity structure between the northern (distances 0–120 km) and southern parts of the profile. The difference in P-wave velocities and Vp/Vs ratio can be followed through the whole crust down to the Moho boundary indicating major tectonic boundaries. Upper crustal velocities seem to vary with the terranes/compositional differences mapped at the surface. The lower layer of the upper crust displays velocities of 6.0–6.1 km/s. Both Paleoproterozoic and Archean terranes are associated with high velocity bodies (6.30–6.35 km/s) at 100 and 200–350 km distances. The Central Lapland greenstone belt and Central Lapland Granitoid complex are associated with a 4 km-thick zone of unusually low velocities (<6.0 km/s) at distances between 120 and 220 km. We interpret the HUKKA 2007 profile to image an old, partly buried, inverted continental rift zone that has been closed and modified by younger tectonic events. It has structural features typical of rifts: inward dipping rift shoulders, undulating thickness of the middle crust, high velocity lower crust and a rather uniform crustal thickness of 48 km.  相似文献