Modern and Holocene hydrographic characteristics of the shallow Kara Sea shelf (Siberia) as reflected by stable isotopes of bivalves and benthic foraminifera.

Simstich, J. and Erlenkeuser, H. and Harms, I. and Spielhagen, R. F. and Stanovoy, V. (2005) Modern and Holocene hydrographic characteristics of the shallow Kara Sea shelf (Siberia) as reflected by stable isotopes of bivalves and benthic foraminifera. Boreas, 34. pp. 252-263. DOI 10.1111/j.1502-3885.2005.tb01099.x

[img] PDF
Modern_and_Holocene_-_Simstich.pdf
Restricted to Registered users only

Download (639kB)

Abstract

River discharge of Ob and Yenisei to the Kara Sea is highly variable on seasonal and interannual time scales. River water dominates the shallow bottom water near the river mouths, making it warmer and less saline but seasonally and interannually more changeable than bottom water on the deeper shelf. This hydrographic pattern shows up in measurements and modelling, and in stable isotope records (d18O, d13C) along the growth axis of bivalve shells and in multiple analyses of single benthic foraminiferal shells. Average isotope ratios increase, but sample-internal variability decreases with water depth and distance from river mouths. However, isotope records of bivalves and foraminifera of a sediment core from a former submarine channel of Yenisei River reveal a different pattern. The retreat of the river mouth from this site due to early Holocene sea level rise led to increasing average isotope values up core, but not to the expected decrease of the in-sample isotope variability. Southward advection of cold saline water along the palaeo-river channel probably obscured the hydrographic variability during the early Holocene. Later, when sediment filled the channel, the hydrographic variability at the core location remained low, because the shallowing proceeded synchronously with the retreat of the river mouth.

Item Type: Article
Uncontrolled Keywords: 2005 AREP 2005 P IA48
Subjects: 01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions: 01 - Climate Change and Earth-Ocean Atmosphere Systems
Journal or Publication Title: Boreas
Volume: 34
Page Range: pp. 252-263
Identification Number: 10.1111/j.1502-3885.2005.tb01099.x
Depositing User: Sarah Humbert
Date Deposited: 17 Aug 2010 13:39
Last Modified: 23 Jul 2013 09:59
URI: http://eprints.esc.cam.ac.uk/id/eprint/1827

Actions (login required)

View Item View Item

About cookies