Collapse of the Hudson Bay ice center and glacio-isostatic rebound

Eastern Hudson Bay is characterized by falling relative sea level as a result of post-glacial isostatic rebound, which makes the region a natural laboratory for rapid forced regression, where the evolution of deltaic systems and offshore sedimentation patterns can be studied. A multidisciplinary approach involving airphoto analysis, offshore geophysical surveys, sediment coring, and facies and diatom analyses was used in this study of the Nastapoka River delta. The delta has formed as a result of the fluvial erosion of emerged Quaternary sediments but is mainly subaqueous. Offshore, in the prodelta zone, the oldest deposits are glaciomarine, laid down when the ice front of the receding Laurentide ice sheet stood on the Nastapoka hills some 77006800 years BP. Lateral equivalents of this glaciomarine unit are presently exposed on land. The shallow-water platform of the delta shows a thin surficial unit of wave-worked sand that overlies fine-grained, deeper water deposits derived from erosion of clay soils in the river catchment a few centuries ago, probably during periods of intense thermokarst activity. As the isostatic uplift continues, the deltaic platform will gradually emerge and be incised by the river channel.

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Shoreline Shrub Population Extension in Response to Recent Isostatic Rebound in Eastern Hudson Bay, Quebec, Canada

Arctic and Alpine Research ◽

10.2307/1551475 ◽

1993 ◽

Vol 25 (1) ◽

pp. 15 ◽

Cited By ~ 10

Author(s):

Iris von Mors ◽

Yves Begin

Keyword(s):

Hudson Bay ◽

Isostatic Rebound

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Precipitation Chemistry and Chemical Limnology of Fertilized and Natural Lakes at Saqvaqjuac, N.W.T.

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f86-140 ◽

1986 ◽

Vol 43 (6) ◽

pp. 1104-1134 ◽

Cited By ~ 28

Author(s):

Harold E. Welch ◽

John A. Legault

Keyword(s):

Late Summer ◽

Precipitation Chemistry ◽

Lower Latitude ◽

Hudson Bay ◽

Total N ◽

Isostatic Rebound ◽

Natural Lakes ◽

Spring Lake ◽

High Concentrations ◽

Rain Events

Precipitation at Saqvaqjuac (northwest coast of Hudson Bay, 60°39′N) had high concentrations of sea salts, was moderately acidic, and had less SO4 and total N than lower latitude precipitation, although SO4 sources were distant. Watershed retention was high for H+, but negative for other elements as a consequence of isostatic rebound. Annual element runoff was a function of the timing of melt runoff and summer rain events because of permafrost. Lake retention of Si was higher than P because of the different times of loading, late summer versus spring. Conservative element mass did not change overwinter except in low-elevation Spring Lake, where residual Cl, Na, and K diffused from the sediments. Phosphorus and N were the only elements incorporated into black ice. As a result of freezeout and incomplete meltwater mixing beneath lake ice, element concentrations were 1.6 times higher in lakes than inflows, and major ion turnover times were 1.5–2.0 times higher than water turnover times.

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Holocene hydro-climatic change and effects on carbon accumulation inferred from a peat bog in the Attawapiskat River watershed, Hudson Bay Lowlands, Canada

Quaternary Research ◽

10.1016/j.yqres.2012.05.013 ◽

2012 ◽

Vol 78 (2) ◽

pp. 275-284 ◽

Cited By ~ 31

Author(s):

Joan Bunbury ◽

Sarah A. Finkelstein ◽

Jörg Bollmann

Keyword(s):

Carbon Accumulation ◽

Testate Amoeba ◽

Hudson Bay ◽

Pollen Record ◽

Medieval Climate Anomaly ◽

Northern Ontario ◽

Peat Core ◽

Hudson Bay Lowlands ◽

Isostatic Rebound

AbstractMultiple proxies from a 319-cm peat core collected from the Hudson Bay Lowlands, northern Ontario, Canada were analyzed to determine how carbon accumulation has varied as a function of paleohydrology and paleoclimate. Testate amoeba assemblages, analysis of peat composition and humification, and a pollen record from a nearby lake suggest that isostatic rebound and climate may have influenced peatland growth and carbon dynamics over the past 6700 cal yr BP. Long-term apparent rates of carbon accumulation ranged between 8.1 and 36.7 g C m− 2 yr− 1 (average = 18.9 g C m− 2 yr− 1). The highest carbon accumulation estimates were recorded prior to 5400 cal yr BP when a fen existed at this site, however following the fen-to-bog transition carbon accumulation stabilized. Carbon accumulation remained relatively constant through the Neoglacial period after 2400 cal yr BP when pollen-based paleoclimate reconstructions from a nearby lake (McAndrews et al., 1982) and reconstructions of the depth to the water table derived from testate amoeba data suggest a wetter climate. More carbon accumulated per unit time between 1000 and 600 cal yr BP, coinciding in part with the Medieval Climate Anomaly.

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