Palynodebris analysis of a shallow core from the Barents Sea     

LTORBJØRN THRONDSEN  TOR BJÆRKE 《Polar research》1983,1(1):43-48

A quantitative study of palynomorphs and palynodebris in a shallow core from the central part of Bjørnøyrenna, western Barents Sea, is presented. The core could be subdivided into a lower part characterized by a complete dominance of reworked plant debris of Mesozoic age and an upper part with considerable input of first cycle algal debris and dinoflagellate cysts. Two hypotheses are suggested to explain this radical change in palynodebris composition. Either it represents a transition from a situation with permanent ice to normal marine conditions, or the absence of first cycle plant debris in the lower part of the core is caused by a masking of this component due to extremely high input of glacially eroded material from the bordering shallow parts of the Barents Sea. The present study shows that palynodebris analysis may contribute important information to the study of composition and depositional environment of Quaternary marine sediments in the area.  相似文献   

Jens Esmark – a pioneer in glacial geology     

BJØRN G. ANDERSEN 《Boreas: An International Journal of Quaternary Research》1992,21(1):97-102

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The Late Quaternary Skagerrak and its depositional environment     

JÖRN THIEDE 《Boreas: An International Journal of Quaternary Research》1987,16(4):425-432

The Skagerrak is a key region for our understanding of the Late Quaternary history of the East North Sea, of the entire Baltic basin and of the adjacent Scandinavian land areas. The depositional history of the postglacial Skagerrak began after the ice margin withdrew from Jutland to close to the modern Norwegian coast around 14 ka B.P. to 13 ka B.P. The Skagerrak was immediately filled by marine waters from the Norwegian Sea, but retained a fjord-like shape until approximately 10.2 ka B.P., when a connection opened across central Sweden to the Baltic Ice Lake. This seaway closed around 9 ka B.P., but a new seaway to the Baltic basin opened subsequently (probably close to 8.5 ka B.P.) through the Danish Belts. At about 10 ka B.P. the Skagerrak 'fjord' also started to change shape due to the flooding of the large former land area under the modern North Sea. Paleo-geography and -bathymetry of these changes can now be quantified in great detail. The young Quaternary sediments of the Skagerrak consist of fine-grained clays with minor amounts of silty and sandy material and are mostly of terrigenous origin, whereas biogenic components in general make up only a minor proportion of the bulk sediment. Prior to 10 ka B.P. a major portion of these deposits originated from the Fennoscandian regions N and E of the Skagerrak, while ice-rafting contributed coarse terrigenous components to the usually fine-grained sediments and while it was filled by brackish surface and cold polar bottom waters. At approximately 10 ka B.P., more temperate waters started to fill the Skagerrak and a good portion of the sediment seems to have originated from areas to the South. The Norwegian Coastal Current can only be documented for the past 7 ka; subtle changes of the pelagic and benthic environments could also be documented for later intervals.  相似文献   

Numerical simulation of the northern Germany storm of 27–28 August 1989     

SIGBJØRN GRØNÅS  NILS GUNNAR KVAMSTØ  ELMER RAUSTEIN 《地球，A辑:动力气象学与海洋学》1994,46(5):635-650

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A new Polish journal on Quaternary reasearch     

BJÖRN E. BERGLUND 《Boreas: An International Journal of Quaternary Research》1980,9(4):282-282

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Leaf area index is the principal scaling parameter for both gross photosynthesis and ecosystem respiration of Northern deciduous and coniferous forests   总被引：1，自引：0，他引：1  

ANDERS LINDROTH  FREDRIK LAGERGREN  MIKA AURELA  BRYNHILDUR BJARNADOTTIR  TORBEN CHRISTENSEN  EBBA DELLWIK  ACHIM GRELLE  REAS IBROM  TORBJÖRN JOHANSSON  HARRY LANKREIJER  SAMULI LAUNIAINEN  TUOMAS LAURILA  MEELIS MÖLDER  EERO NIKINMAA  KIM PILEGAARD  BJARNI D. SIGURDSSON  TIMO VESALA 《Tellus. Series B, Chemical and physical meteorology》2008,60(2):129-142

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Early Holocene history of the southwestern Baltic Sea: the Ancylus Lake stage   总被引：1，自引：0，他引：1  

J&#;RN BO JENSEN  OLE BENNIKE  RZEJ WITKOWSKI  WOLFRAM LEMKE  ANTOON KUIJPERS 《Boreas: An International Journal of Quaternary Research》1999,28(4):437-453

One of the most discussed stages in the history of the Baltic Sea is the Ancylus Lake phase. This paper presents detailed information from the Darss Sill threshold area as well as the adjacent basins, i.e. the Mecklenburg Bay and Arkona Basin located in the southwesternmost Baltic. The threshold area was transgressed at the Baltic Ice Lake maximum phase and during the following regression about 10.3 ka BP a river valley was incised in the Darss Sill to a level of 23-24 m below present sea level (b.s.l.). Preboreal sediments in the study area show lowstand basin deposition in the Arkona Basin and the existence of a local lake in Mecklenburg Bay. The lowstand system is followed by the Ancylus Lake transgression that reached a maximum level of 19 m b.s.l. Thus, at the maximum level the water depth was about 5 m over the threshold, and the shore level fall during the Ancylus Lake regression must be in the same range. The Darss Sill area is the key area for drainage of the Ancylus Lake, and if the previously suggested regression of 8-10 m in southeastern Sweden is to be achieved, isostatic rebound must also play a role. The existence of the so-called Dana River in the Darss Sill area cannot be supported by our investigations. We observed no signs of progressive erosion of the Darss Sill area in the Early Holocene, and there are no prograding systems in Mecklenburg Bay that can be related to the Ancylus Lake regression. On the contrary, local lakes developed in Mecklenburg Bay and in the Darss Sill threshold area. In the Darss Sill area, marl was deposited in a lake in the valley that developed after the final drainage of the Baltic Ice Lake. Studies of diatoms and macrofossils, combined with seismic interpretation and radiocarbon dating, provide detailed information about the chronology and the relative shore level of these lake phases as well as about environmental conditions in the lakes.  相似文献   

Full-glacial — late-glacial palaeoclimate of the Southern Andes: evidence from pollen,beetle and glacial records     

CALVIN J. HEUSSER  THOMAS V. LOWELL  LINDA E. HEUSSER  ARTURO HAUSER  BJ RN G. ANDERSEN  GEORGE H. DENTON 《第四纪科学杂志》1996,11(3):173-184

Palaeoecological studies carried out in the Chilean Lake District and Chilotan Archipelago (41°–43°S) record full-glacial and late-glacial pollen assemblages beginning just after 21000 and beetle assemblages after 18000, both sets extending until 10000 ¹⁴C yr BP. Pollen records indicate that Subantarctic Parkland, the vegetation of the early millennia of record, changed after about 14000 yr BP to become open woodland and later North Patagonian Evergreen Forest. Assemblages of plants and beetles, responding more or less in unison to a strong rise in temperature (≥ 6°C), behaved in accord at around 14000 until 13000–12500 yr BP, the beetle fauna displaying a marked increase in obligate forest types. During full-glacial conditions (17400–16100 and 15300 and 14400 yr BP) and in the late-glacial interval (after about 13000 yr BP), however, climate evidently coerced populations dissimilarly, the pollen sequence showing an increase in plant taxa indicative of colder climate, whereas the beetle fauna underwent little or no variation. Contrasting climate modes implied by plants and beetles may be attributed to differential responses to apparent low-order temperature changes (≤ 2–3°C).  相似文献   

The Northeast Arctic cod stock's place in the Barents Sea ecosystem in the 1980s: an overview   总被引：1，自引：0，他引：1  

SIGBJØRN MEHL 《Polar research》1991,10(2):525-534

Just after World War II the size of the Northeast Arctic cod ( Gadus morhua ) stock was about 6 million tonnes, but at the beginning of the 1980s the stock had been reduced to 1 million tonnes, due mainly to the excessively high fishing-mortality. Nevertheless, the stock produced strong year classes at the 0-group stage in the relatively warm period 1983-1985. At the same time, individual growth in the cod stock was good, and in 1986 the stock size increased to over 1.5 million tonnes.
However, the cod preyed increasingly on the capelin ( Mallotus villosus ) present, and by the end of 1986 the capelin stock was seriously depleted. The cod compensated for the loss of capelin by preying more intensively on other food items, including smaller cod. Cannibalism increased by a factor of three from 1984 to 1986, and this is one important reason why the 1984 and 1985 year classes did not recruit to the fisheries as expected. Individual growth was dramatically reduced, and the average fish weight decreased by about 50% in most age groups. Because the quotas are in tonnes, more fish than expected were caught. This resulted in serious management problems and led to reductions both in stock size and quotas compared to the optimistic prognosis of the mid-1980s.  相似文献   

Quaternary vertebrates in Hungary     

BJÖRN KURTÉN 《Boreas: An International Journal of Quaternary Research》1988,17(3):328-328

Book reviewed in this article:
Janossy, D. 1986: Pleistocene Vertebrate Faunas in Hungary.  相似文献