scholarly journals Climatic Influences of Deglacial Drainage Changes in Southern Canada at 10 to 8 ka Suggested by Pollen Evidence

2007 ◽  
Vol 46 (3) ◽  
pp. 255-272 ◽  
Author(s):  
Thane W. Anderson ◽  
C.F. Michael Lewis
Keyword(s):  
Great Lakes ◽  
Water Bodies ◽  
Hudson Bay ◽  
Lake Agassiz ◽  
Climatic Effects ◽  
Cool Period ◽  
Surface Areas ◽  
Summer Warming ◽  
Lake Waters ◽  
Lake Minong

ABSTRACT Enhanced meltwater discharge from proglacial lakes Agassiz and Barlow-Ojibway at about 9.6 to 8.3 ka BP. created cold localized climates over downstream water bodies, specifically Lake Minong and Mattawa phase lakes in the Great Lakes and Goldthwait Sea in the Gulf of St. Lawrence. The cooling effect of the meltwater drainage suppressed summer warming of the surface lake waters, reduced the growing season and thus altered the vegetation composition in the surrounding land areas. The vegetation responded in different ways as evidenced by five variants from the normal pollen succession.The pollen anomalies are most pronounced where the effect of increased meltwater discharge had a strong influence, such as within or along the margins of Lake Agassiz, Mattawa phase lakes, and the Goldthwait Sea, or in their lee areas, especially where these water bodies intersected ecotonal boundaries. Climatic effects were minimal or non-existent where the water surface areas were restricted such as the channelized drainage routes of the Ottawa and St. Lawrence rivers. Diversion of Lakes Agassiz and Barlow-Ojibway drainage to Hudson Bay after about 8.4 ka BP reinstated summer warming of the surface water in the Great Lakes-St. Lawrence system bringing the 9.6-8.3 ka cool period to a close.

LAKE AGASSIZ DRAINAGE BRACKETED HOLOCENE HUDSON BAY ICE SADDLE COLLAPSE

2020 ◽  
Author(s):  
Michelle Trommelen ◽  
◽  
Tyler Hodder ◽  
Samuel E. Kelley
Keyword(s):  
Hudson Bay ◽  
Lake Agassiz

scholarly journals Thermokarst lake waters across the permafrost zones of western Siberia

2014 ◽  
Vol 8 (4) ◽  
pp. 1177-1193 ◽  
Author(s):  
R. M. Manasypov ◽  
O. S. Pokrovsky ◽  
S. N. Kirpotin ◽  
L. S. Shirokova
Keyword(s):  
Western Siberia ◽  
Chemical Elements ◽  
Chemical Compositions ◽  
Thermokarst Lakes ◽  
Thermokarst Lake ◽  
Surface Areas ◽  
Discontinuous Permafrost ◽  
Latitudinal Position ◽  
Hydrochemical Composition ◽  
Lake Waters

Abstract. This work describes the hydrochemical composition of thermokarst lake and pond ecosystems, which are observed in various sizes with different degrees of permafrost influence and are located in the northern part of western Siberia within the continuous and discontinuous permafrost zones. We analysed the elemental chemical composition of the lake waters relative to their surface areas (from 10 to 106 m2) and described the elemental composition of the thermokarst water body ecosystems in detail. We revealed significant correlations between the Fe, Al, dissolved organic carbon (DOC) and various chemical elements across a latitude gradient covering approximately 900 km. Several groups of chemical elements that reflect the evolution of the studied water bodies were distinguished. Combining the data for the studied latitude profile with the information available in the current literature demonstrated that the average dissolved elemental concentrations in lakes with different areas depend specifically on the latitudinal position, which is presumably linked to (1) the elements leached from frozen peat, which is the main source of the solutes in thermokarst lakes, (2) marine atmospheric aerosol depositions, particularly near the sea border and (3) short-range industrial pollution by certain metals from the largest Russian Arctic smelter. We discuss the evolution of the chemical compositions observed in thermokarst lakes during their formation and drainage and predict the effect that changing the permafrost regime in western Siberia has on the hydrochemistry of the lakes.

Paleohydrology of the upper Laurentian Great Lakes from the late glacial to early Holocene

2009 ◽  
Vol 71 (3) ◽  
pp. 397-408 ◽  
Author(s):  
Andy Breckenridge ◽  
Thomas C. Johnson
Keyword(s):  
Great Lakes ◽  
Lake Michigan ◽  
Lake Superior ◽  
Late Glacial ◽  
Lake Huron ◽  
Michigan Basin ◽  
Great Lakes Basin ◽  
Lake Agassiz ◽  
Sharp Drop ◽  
Freshwater Fluxes

AbstractBetween 10,500 and 9000 cal yr BP, δ18O values of benthic ostracodes within glaciolacustrine varves from Lake Superior range from − 18 to − 22‰ PDB. In contrast, coeval ostracode and bivalve records from the Lake Huron and Lake Michigan basins are characterized by extreme δ18O variations, ranging from values that reflect a source that is primarily glacial (∼ − 20‰ PDB) to much higher values characteristic of a regional meteoric source (∼ − 5‰ PDB). Re-evaluated age models for the Huron and Michigan records yield a more consistent δ18O stratigraphy. The striking feature of these records is a sharp drop in δ18O values between 9400 and 9000 cal yr BP. In the Huron basin, this low δ18O excursion was ascribed to the late Stanley lowstand, and in the Lake Michigan basin to Lake Agassiz flooding. Catastrophic flooding from Lake Agassiz is likely, but a second possibility is that the low δ18O excursion records the switching of overflow from the Lake Superior basin from an undocumented northern outlet back into the Great Lakes basin. Quantifying freshwater fluxes for this system remains difficult because the benthic ostracodes in the glaciolacustrine varves of Lake Superior and Lake Agassiz may not record the average δ18O value of surface water.

Preferential pathways of phosphorus movement from agricultural land to water bodies in the Canadian Great Lakes basin: A predictive tool

2011 ◽  
Vol 91 (3) ◽  
pp. 361-374 ◽  
Author(s):  
Suzanne Edith Allaire ◽  
Eric van Bochove ◽  
Jean-Thomas Denault ◽  
Humaira Dadfar ◽  
Georges Thériault ◽  
...  
Keyword(s):  
Great Lakes ◽  
Agricultural Land ◽  
Water Bodies ◽  
Great Lakes Basin ◽  
Predictive Tool ◽  
Preferential Pathways

VARIATION IN NUMBER OF DORSAL SPINES IN THE BROOK STICKLEBACK, EUCALIA INCONSTANS

1958 ◽  
Vol 36 (2) ◽  
pp. 127-129 ◽  
Author(s):  
G. H. Lawler
Keyword(s):  
Great Lakes ◽  
Hudson Bay ◽  
Great Lakes Region ◽  
Brook Stickleback

The brook stickleback, Eacalia inconstans (Kirtland), is usually described as possessing five or six dorsal spines and the species is commonly called the five-spine stickleback. In Homing Lake, Manitoba, fish with six dorsal spines predominate. The occurrence of sticklebacks with a high number of dorsal spines is noted from other Manitoba lakes and to a lesser extent in samples from some Ontario lakes. Indications are that the dorsal spines are more numerous in fish from the Hudson Bay drainage than from the Great Lakes region. An increase in the number of dorsal spines with increasing latitude is apparent.

scholarly journals Impact of climate change and anthropogenic interventions on natural vis-à-vis human resources in Kashmir, India – An overview

2016 ◽  
Vol 8 (1) ◽  
pp. 489-493
Author(s):  
Peerzada Ishtiyak ◽  
Mohan Reddy ◽  
Shiv Panse ◽  
Irfan Wani ◽  
Quadri Javeed Ahmad Peer
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Human Resources ◽  
Natural Resources ◽  
Forest Cover ◽  
Climatic Variability ◽  
Water Bodies ◽  
Climatic Effects ◽  
Dry Land ◽  
The World

Climate change is one of the biggest challenges the world is facing today and it has the potential to create havoc with the agrarian livelihoods across the globe. Therefore, this paper attempts to explain the probable impacts of human induced climate change on natural resources in Kashmir, India. An ample amount of literature was reviewed meticulously to ascertain the impacts of climatic variability on natural resources vis-a-vis agriculture, biodiversity and water bodies as well as other common issues related to human resources in Kashmir. Loss of certain indigenous food varieties (i.e. nick cheena), reduction in natural forest cover (less than 11%) and loss of important water resources has aggravated the already dilapidated situation in this most vulnerable state of India. Scientific evidences revealed that there will be more devastating climatic effects on natural resources in Kashmir- India, which will fall disproportionately on poor communities, particularly dry land farmers, forest dwellers and fishermen of the state.

Contamination Hazard from Waste Disposal Sites near Receding Great Lakes Shorelines

1989 ◽  
Vol 24 (1) ◽  
pp. 81-100 ◽  
Author(s):  
J.P. Coakley
Keyword(s):  
Great Lakes ◽  
Groundwater Contamination ◽  
Waste Disposal ◽  
Lake Erie ◽  
Lake Ontario ◽  
Waste Site ◽  
Shore Zone ◽  
Upper Great Lakes ◽  
Lake Waters ◽  
Hydrogeological Information

Abstract Of the approximately 4000 waste disposal sites in Ontario, more than 230 are located within 5 km of the shoreline of the lower Great Lakes. Sixty sites are within 1 km of the shore. Unlike the more resistant bedrock shores of the Upper Great Lakes, the shoreline between Midland (Georgian Bay) and Kingston (Lake Ontario) is composed primarily of unlithified glacial deposits, and thus is prone to significant erosion. This report presents an examination of the potential for contamination of nearshore lake waters either directly through shoreline recession at the waste site, or indirectly through the transport to the lake of leachates from the nearby sites via groundwater discharges. Recession-related hazards were identified at three sites (two on Lake Ontario and one on Lake Erie). Groundwater contamination hazards were harder to identify due to insufficient subsurface and hydrogeological information. However, 31 sites, less than 0.2 km from the shore, were identified as potentially hazardous; 19 of these were located in the northern Lake Ontario shore zone.

Correlation of sea-level curves for the Lower Silurian of the Bruce Peninsula and Lake Timiskaming District (Ontario)

1982 ◽  
Vol 19 (5) ◽  
pp. 962-974 ◽  
Author(s):  
Valerie R. Colville ◽  
Markes E. Johnson
Keyword(s):  
Great Lakes ◽  
Sea Level ◽  
Hudson Bay ◽  
Strong Correlations ◽  
The South ◽  
Upper Peninsula ◽  
Level Curves ◽  
Lower Silurian ◽  
Hudson Bay Lowlands ◽  
Open Connection

Paleobathymetric interpretation of strata from the Bruce Peninsula and Lake Timiskaming District of Ontario shows strong correlations with data from the Michigan Upper Peninsula and Ontario's Manitoulin Island. Three to four cycles of fluctuating sea level occurred during Early Silurian (Llandoverian) time throughout much of the northern Great Lakes area, and involved the highly regular replacement of ostracode–vermiform, coral–algal, and pentamerid communities by one another. Although exposure is more limited than on Manitoulin Island or the Michigan Upper Peninsula, important clues regarding Early Silurian geography are found in strata of the Bruce Peninsula and Lake Timiskaming District. Continued thinning of stratigraphic units and an increased incidence of disconformities from north to south on the Bruce Peninsula suggest the episodic rise of the Algonquin Arch farther to the south and west. Contrary to earlier paleogeographic reconstructions, the patterns of community changeovers preserved in the Silurian outlier of the Lake Timiskaming District indicate a persistent, open connection between the seas of the northern Great Lakes area and the Hudson Bay Lowlands. This interpretation is more in keeping with recent paleontologic work on faunal distributions.

A post-Lake Minong transgressive event on the north shore of Lake Superior, Ontario: possible evidence of Lake Agassiz inflow

1994 ◽  
Vol 31 (11) ◽  
pp. 1638-1641 ◽  
Author(s):  
Brian A. M. Phillips ◽  
Philip W. Fralick
Keyword(s):  
Water Level ◽  
Lake Superior ◽  
Lower Portion ◽  
Fluvial Sediments ◽  
Lake Agassiz ◽  
North Shore ◽  
The North ◽  
Level Oscillation ◽  
Water Level Oscillation ◽  
Lake Minong

Modification of an ice-contact delta built on the margin of Lake Minong (9500 BP) is ascribed to a transgressive event. Reworking of fluvial sediments by wave action and the infilling of the lower end of a distributary valley demonstrate a post-Minong transgression and reoccupation of the lower portion of the delta. Estimated to be in the order of 18 m, this water-level oscillation may represent evidence of one of several catastrophic discharges of Lake Agassiz into the Superior basin, proposed to have occurred between 9.5 and 8.0 ka BP.

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