Decadal- to millennial-scale variability of Arctic–Subarctic oceans and adjacent lands: a contribution of the Polar Climate Stability Network of Canada to the International Polar YearThis article introduces a series of papers published in this Special Issue on the theme Polar Climate Stability Network. It is also in memorium of Dr. Roy M. (“Fritz”) Koerner (1932–2008)

2008 ◽  
Vol 45 (11) ◽  
pp. 1199-1201 ◽  
Author(s):  
Claude Hillaire-Marcel
Keyword(s):  
Special Issue ◽  
Polar Climate ◽  
Climate Stability ◽  
International Polar ◽  
Millennial Scale

High-resolution paleomagnetic secular variation and relative paleointensity records from the western Canadian Arctic: implication for Holocene stratigraphy and geomagnetic field behaviourThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.GEOTOP Contribution 2008-0024.

2008 ◽  
Vol 45 (11) ◽  
pp. 1265-1281 ◽  
Author(s):  
Francesco Barletta ◽  
Guillaume St-Onge ◽  
James E.T. Channell ◽  
André Rochon ◽  
Leonid Polyak ◽  
...  
Keyword(s):  
Dipole Moment ◽  
High Resolution ◽  
Secular Variation ◽  
Geomagnetic Field ◽  
Special Issue ◽  
Polar Climate ◽  
Climate Stability ◽  
Relative Paleointensity ◽  
Holocene Stratigraphy ◽  
Field Behaviour

Two piston cores recovered from the Chukchi and the Beaufort seas document Arctic Holocene geomagnetic field behaviour and highlight the potential of secular variation and relative paleointensity as a regional chronostratigraphic tool. Several centennial- to millennial-scale Holocene declination and inclination features can be correlated in both cores, with other high-resolution western North American lacustrine and volcanic paleomagnetic records and with records of changes in Earth’s dipole moment, supporting the geomagnetic origin of these features and implying that they are associated with changes in Earth’s dipole moment.

Postglacial evolution of a Pacific coastal fjord in British Columbia, Canada: interactions of sea-level change, crustal response, and environmental fluctuations — results from MONA core MD02-2494This article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.

2008 ◽  
Vol 45 (11) ◽  
pp. 1345-1362 ◽  
Author(s):  
Audrey Dallimore ◽  
Randolph J. Enkin ◽  
Reinhard Pienitz ◽  
John R. Southon ◽  
Judith Baker ◽  
...  
Keyword(s):  
British Columbia ◽  
Sea Level ◽  
Radiocarbon Dates ◽  
Polar Climate ◽  
The Core ◽  
Mantle Viscosity ◽  
Climate Stability ◽  
Viscosity Models ◽  
New Information ◽  
Effingham Inlet

The sedimentary record in a 40.9 m giant (Calypso) piston core (MD02-2494) raised from the inner basin within Effingham Inlet, British Columbia, Canada, during the 2002 Marges Ouest Nord Américaines (MONA) campaign, spans from 14 360 14C years BP (17 300 calibrated calendar (cal.) years BP) to about nine centuries before present. The core archives changes in sedimentation and sea level immediately following deglaciation of the Late Wisconsin Fraser Glaciation, which peaked about 15 000 14C years BP. The presence of the Mazama Ash in the core anchors a detailed chronology based on 49 radiocarbon dates and seven Pleistocene paleomagnetic secular variation correlations. Diatom assemblages identify a marine–freshwater–marine transition in the basin, which occurred 11 630 14C years BP (13 500 cal. years BP). At this time, a bedrock sill, presently at 46 m depth, was briefly exposed as sea level fell and then rose again during isostatic crustal adjustments. These data constrain a new sea-level curve for the outer coast of Vancouver Island covering the past 12 000 14C years BP (14 000 cal. years BP), providing new information on the nature of deglaciation along the west coast of Canada and informing interpretations of regional paleoceanographic records and mantle viscosity models.

scholarly journals The Changing Arctic Ocean: An Introduction to the Special Issue on the International Polar Year (2007–2008)

Oceanography ◽  
2011 ◽  
Vol 24 (3) ◽  
pp. 14-16 ◽  
Author(s):  
Joseph Ortiz ◽  
Kelly Falkner ◽  
Patricia Matrai ◽  
Rebecca Woodgate
Keyword(s):  
Arctic Ocean ◽  
Special Issue ◽  
International Polar Year ◽  
International Polar

Geochemical reconstruction of Pacific decadal variability from the eastern North Pacific during the HoloceneThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.

2008 ◽  
Vol 45 (11) ◽  
pp. 1317-1329 ◽  
Author(s):  
Tara S. Ivanochko ◽  
Stephen E. Calvert ◽  
Richard E. Thomson ◽  
Thomas F. Pedersen
Keyword(s):  
North Pacific ◽  
Decadal Variability ◽  
High Elevation ◽  
Early Holocene ◽  
Aleutian Low ◽  
Polar Climate ◽  
Climate Stability ◽  
The Pacific ◽  
Age Model ◽  
Effingham Inlet

Determining climate variations over the Holocene requires high-resolution records with well-developed age models. A 40 m long marine sediment core raised from Effingham Inlet, an anoxic fjord on the west coast of Vancouver Island, British Columbia, Canada, yields such a record. Forty six 14C accelerator mass spectrometry (AMS) dates determined from terrestrial plant material form the age model. Downcore sampling at both 5 cm (20 year) and 1.5 cm (7 year) resolution indicates that high-frequency oceanographic variability has prevailed at this site over the last 10 000 years. Spectral analysis of wt.% opal, a proxy for diatom productivity in the basin, reveals the bidecadal and pentadecadal periods of the Pacific decadal oscillation (PDO) – North Pacific index (NPI) that are related to changes in the strength of the Aleutian Low. Coherence analysis between the Effingham Inlet data and δ18O records from Jellybean Lake (a high elevation site in southwest Yukon) indicates regional coherence at periods of 45, 70, and 510 years between productivity in Effingham Inlet and changes in the Aleutian Low strength. Over the entire Holocene, the strength of decadal variability has changed. Both 20- and 50-year periods are present to some degree in the early Holocene, and only the 50 year period is evident in the late Holocene. These data imply that regime shifts would have been more frequent in the early Holocene relative to the last several thousand years.

210Pb–226Ra–230Th systematics in very low sedimentation rate sediments from the Mendeleev Ridge (Arctic Ocean)This article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.GEOTOP Publication 2008-0031.

2008 ◽  
Vol 45 (11) ◽  
pp. 1207-1219 ◽  
Author(s):  
Christelle Not ◽  
Claude Hillaire-Marcel ◽  
Bassam Ghaleb ◽  
Leonid Polyak ◽  
Dennis Darby
Keyword(s):  
Arctic Ocean ◽  
Water Column ◽  
Natural Radionuclides ◽  
The Arctic ◽  
Sedimentation Rates ◽  
Overlying Water ◽  
Fine Grained ◽  
Polar Climate ◽  
Climate Stability ◽  
Precise Knowledge

U-series isotope behaviour in subsurface sediment of the Arctic Ocean is investigated based on high resolution measurements of natural radionuclides (210Pb, 226Ra, 230Th) and a few analyses of anthropogenic 137Cs in cores collected during the 2005 Healy-Oden Trans-Arctic Expedition (HOTRAX). Cores from the Mendeleev Ridge, representing distinct bathymetric settings, are analyzed in more detail as a means to assess the dating potential of such radionuclides at sites characterized by very low sedimentation rates (∼3 mm ka–1). The sediment consists of variable proportions of fine-grained carbonates, clays, and ice-rafted debris and shows excesses in 210Pb (210Pbxs) over parent 226Ra content, down to ∼1 cm below core top. This 210Pbxs distribution is due to shallow mixing by benthic organisms and (or) diffusion from the sediment–water interface, as also indicated by 137Cs activities. From ∼1 to 7 cm downcore, 210Pb activities closely follow 226Ra activities. Below 7 cm downcore, 226Ra activities are controlled by variable excesses in parent 230Th (230Thxs) resulting from its scavenging in the overlying water column. 226Ra diffusion is observed towards the water column occuring from the upper ∼7 cm of sediment below the seafloor (with a flux of ∼0.043 disintegrations per minute (dpm) cm–2 a–1) and deeper in the sediment below 230Thxs peaks but with lesser fluxes. Both cores show identical 210Pb profiles despite their 1 km bathymetric difference. This suggests negligible 230Th and 210Pb scavenging below water depths of ∼1.6 km, i.e., the bathymetry of the shallower core. In such settings where sedimentation rates are very low and vertical particle rain is the major sediment source, estimates of the actual 210Pbxs require precise knowledge of the 226Ra-supported fraction, which is controlled by 230Thxs, Ra diffusion, and thus sedimentation rates and porosity.

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