Organic carbon isotope ratios of sea surface sediments and sea-ice from the Amerasian Continental shelf


Autoria(s): Naidu, A Sathy; Cooper, Lee W; Finney, Bruce P; Macdonald, Robie W; Alexander, Clark; Semiletov, Igor P
Cobertura

MEDIAN LATITUDE: 70.183640 * MEDIAN LONGITUDE: -150.807252 * SOUTH-BOUND LATITUDE: 64.416700 * WEST-BOUND LONGITUDE: -178.250000 * NORTH-BOUND LATITUDE: 74.583300 * EAST-BOUND LONGITUDE: -126.483300

Data(s)

29/01/2000

Resumo

Organic matter origins are inferred from carbon isotope ratios (delta13C) in recent continental shelf sediments and major rivers from 465 locations from the north Bering-Chukchi-East Siberian-Beaufort Sea, Arctic Amerasia. Generally, there is a cross-shelf increase in delta13C, which is due to progressive increased contribution seaward of marine-derived organic carbon to surface sediments. This conclusion is supported by the correlations between sediment delta13C, OC/N, and delta15N. The sources of total organic carbon (TOC) to the Amerasian margin sediments are primarily from marine water-column phytoplankton and terrigenous C3 plants constituted of tundra taiga and angiosperms. In contrast to more temperate regions, the source of TOC from terrigenous C4 and CAM plants to the study area is probably insignificant because these plants do not exist in the northern high latitudes. The input of carbon to the northern Alaskan shelf sediments from nearshore kelp community (Laminaria solidungula) is generally insignificant as indicated by the absence of high sediment delta13C values (-16.5 to -13.6 per mil) which are typical of the macrophytes. Our study suggests that the isotopic composition of sediment TOC has potential application in reconstructing temporal changes in delivery and accumulation of organic matter resulting from glacial-interglacial changes in sea level and environments. Furthermore, recycling and advection of the extensive deposits of terrestrially derived organic matter from land, or the wide Amerasian margin, could be a mechanism for elevating total CO2 and pCO2 in the Arctic Basin halocline.

Formato

application/zip, 2 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.712053

doi:10.1594/PANGAEA.712053

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Naidu, A Sathy; Cooper, Lee W; Finney, Bruce P; Macdonald, Robie W; Alexander, Clark; Semiletov, Igor P (2000): Organic carbon isotope ratios (d13C) of Arctic Amerasian Continental shelf sediments. International Journal of Earth Sciences, 89(3), 522-532, doi:10.1007/s005310000121

Palavras-Chave #Bathy depth; C/N; Calculated; Carbon, organic, total; Carbon/Nitrogen ratio; Comment; d13C Corg; d15N; delta 13C, organic carbon; delta 15N; Depth; Depth, bathymetric; DEPTH, ice/snow; DEPTH, sediment/rock; Depth ice/snow; Element analyser CHN, Perkin-Elmer 240B; Isotope ratio mass spectrometry; Label; Latitude; LATITUDE; Longitude; LONGITUDE; map code; Mass spectrometer Europa Scientific 20/2; Nitrogen, total; Sample code/label; Sample ID; TN; TOC
Tipo

Dataset