SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Hall Per) srt2:(1995-1999)"

Sökning: WFRF:(Hall Per) > (1995-1999)

  • Resultat 1-6 av 6
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Anderson, Leif G., et al. (författare)
  • The effect of the Siberian tundra on the environment of the shelf seas and the Arctic Ocean
  • 1999
  • Ingår i: Ambio. - 0044-7447. ; 28:3, s. 270-280
  • Tidskriftsartikel (refereegranskat)abstract
    • The Tundra Ecology -94 expedition investigated inflow of inorganic and organic carbon to the shelf seas by river runoff, and its transformation by biochemical processes in seawater and sediment. In addition, anthropogenic radionuclides, 137Cs, 90Sr, and 239,240Pu, were studied in water and sediments. The distribution of dissolved inorganic carbon indicates that the majority of the Ob and Yenisey discharges flow into the Laptev Sea before entering the central Arctic Ocean. The sediment study shows that there is a marked difference in benthic oxygen uptake, efflux of dissolved inorganic carbon and nutrients between localities. 137Cs activity from the Chernobyl accident is 30% in the Barents, Kara, and Laptev Seas. 137Cs increased from 5-8 Bq m-3 in Barents Sea, 5-13 Bq m-3 in the Kara Sea to 8-15 Bq m-3 in the Laptev Sea, but with locally low concentrations at the river mouths. Corresponding values for 90Sr were 2.5, 3, and 4 Bq m-3, respectively.
  •  
2.
  •  
3.
  • Dahllöf, Ingela, 1963, et al. (författare)
  • Long-term effects of tri-n-butyltin on the function of a marine sediment system
  • 1999
  • Ingår i: Marine Ecology Progress Series. ; 188, s. 1-11
  • Tidskriftsartikel (refereegranskat)abstract
    • The effect of tri-n-butyl-tin (TBT) was studied in a 5 mo experiment using intact coastal sediment communities in a boxcosm system. TBT-spiked sediment was added in a geometrical series between 0.0065 and 300 mu mol TBT m(-2) to a sediment that already had a background TBT concentration. Fluxes of ammonium, nitrate, phosphate, silicate and oxygen were used as effect indicators for the entire sediment system, integrating the function of all fauna and micro-organisms present. Changes in flux patterns were analysed in order to evaluate the effect of TBT on the whole sediment system using a non-parametric analysis of similarities (ANOSIM), based on Bray-Curtis similarity indices. Effects were seen at the lowest additions of 6.5 nmol TBT m(-2) as changes in flux pattern compared to the control sediments. The separate nutrient fluxes were also evaluated, showing an early response in a reduced ammonium flux and a stimulated nitrate flux for most of the TBT additions. The initial response indicated immediate effects on the microbial part of the sediment community. The fluxes changed with time in all sediment boxes, but the changes were different in sediments with added TBT compared to the control sediment. These changes showed that the heterotrophic capability to degrade organic matter and autotrophic nitrification was reduced during the 5 mo of the experiment. In the 3 highest additions, the abundance of macrofauna was reduced at the very beginning of the experiment, whereas fauna in the intermediate additions seemed to become stressed with time as indicated by an increased oxygen consumption. This study shows that minute additions of fresh TBT to an already contaminated sediment have effects on the function of the sediment system at nominal concentrations of nmol of TBT added per square metre. These additions were well below the current detection limits for TBT in sediments.
  •  
4.
  •  
5.
  • Ingolfsson, O., et al. (författare)
  • Antarctic glacial history since the Last Glacial Maximum: an overview of the record on land
  • 1998
  • Ingår i: Antarctic Science. - 1365-2079. ; 10:3, s. 326-344
  • Tidskriftsartikel (refereegranskat)abstract
    • This overview examines available circum-Antarctic glacial history archives on land, related to developments after the Last Glacial Maximum (LGM). It considers the glacial-stratigraphic and morphologic records and also biostratigraphical information from moss banks, lake sediments and penguin rookeries, with some reference to relevant glacial marine records. It is concluded that Holocene environmental development in Antarctica differed from that in the Northern Hemisphere. The initial deglaciation of the shelf areas surrounding Antarctica took place before 10 000 14C yrs before present (BP), and was controlled by rising global sea level. This was followed by the deglaciation of some presently ice-free inner shelf and land areas between 10 000 and 8000 yr BP. Continued deglaciation occurred gradually between 8000 yr BP and 5000 yr BP. Mid-Holocene glacial readvances are recorded from various sites around Antarctica. There are strong indications of a circum-Antarctic climate warmer than today 4700-2000 yr BP. The best dated records from the Antarctic Peninsula and coastal Victoria Land suggest climatic optimums there from 4000-3000 yr BP and 3600-2600 yr BP, respectively. Thereafter Neoglacial readvances are recorded. Relatively limited glacial expansions in Antarctica during the past few hundred years correlate with the Little Ice Age in the Northern Hemisphere.
  •  
6.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-6 av 6

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy