Glacial History, Paleo-geography and Paleo-environments of North America
Activity Rationale
Drs. Alain Plouffe (left) and Stephen Wolfe (right) receive NRCan-ESS Merit Awards from Mark Corey (centre) for exceptional achievement related to this activity.
Looking at past climatic, environmental, and geographic data is essential for assessing the potential future impacts associated with climate change. Under this activity, a collection of papers was published that provide past climate change scenarios. These paleo-scenarios will assist in evaluating the potential response of specific regions or environments to climate change, which will help guide adaptation options.
Leader: Stephen Wolfe
The Topic
The purpose of this activity was to produce and publish a suite of papers on the topic of glacial and post-glacial environmental change in glaciated North America as two special issues in Géographie physique et Quaternaire (GpQ) in 2006-07. These issues were dedicated to Dr. Vic Prest, formerly of the Geological Survey of Canada. The papers contain fundamental background information with respects to paleo-climatic and paleo-environmental changes in northern North America since deglaciation.
Géographie physique et Quaternaire, Vol. 58, no. 2-3 and Vol. 59, no. 2-3 publications on the glacial history, paleogeography and paleoenvironments in glaciated North America.
The papers included the efforts of 28 authors from the Geological Survey of Canada, involved in 13 out of the 19 papers. The majority of the papers stem from four years of intensive research under Paleo-Environmental Records of Climate Change, a project within the former Reducing Canada’s Vulnerability to Climate Change program.
Paleo-project contributors included David Fisher, Christian Zdanowicz, Jocelyn Bourgeois, Roy Koerner (emeritus), John Sekerka, Mike Demuth, James Zheng, Tom James, Mike Lewis (emeritus), John Shaw, Steve Blasco, Barbara Medioli, Aruna Dixit, Art Dyke, Doug Hodgson, Vaughn Barrie, Kim Conway and Stephen Wolfe. In addition, other GSC contributors (past and present) included: Alain Plouffe, Denis St-Onge (emeritus), Isabelle McMartin, Penny Henderson (former GSC), Lynda Dredge, Rod Smith, Thane Anderson (former GSC), Jean Veillette, Dave Sharpe and Hazen Russell.
Results
A number of papers represent significant outputs from this activity, especially with regards to sea-level/lake level histories and paleogeographies, and (late) Holocene climate and moisture regimes. In addition, the paleo-biome reconstructions presented herein represents a landmark contribution to Canadian Quaternary environmental history. A few highlights regards to the project are as follows:
Please note that subscriptions may be required for access to some articles. To request a copy of publications, or for any more information, please contact: Stephen Wolfe
Paleo-geography Publications
- In the paper Relative Sea-Level Change in the Northern Strait of Georgia, British Columbia, detailed evidence and geochronology is presented that documents the post-glacial uplift and sea level history in the northern Strait of Georgia, British Columbia.
- In Atlantic Canada, the relative sea-level history for northwestern Newfoundland is documented in the paper Late Quaternary Relative Sea-Level Change on the West Coast of Newfoundland. This paper conveys an improved understanding of the crust’s response to glacial activity.
Paleogeography of Atlantic Canada 13,000 years before present, showing glacial ice cover, emergent areas (in green) and the related continental shelves. Larger image
- New geomorphic evidence of postglacial terrestrial environments on the continental shelves of Atlantic Canada is presented in the paper Geomorphic Evidence of Postglacial Terrestrial Environments on Atlantic Canadian Continental Shelves. This paper highlights multibeam sonar evidence of submerged geomorphic features, including fluvial features, deltas, and coastlines, and places these into the context of post-glacial and relative sea-level history.
- A synthesis of deglacial marine and lake-level elevations for North America and Greenland is presented in the paper North American Deglacial Marine- and Lake-Limit Surfaces. The purpose of this paper is to derive information about the rate and pattern of the last deglaciation, and to provide possible targets for validating geophysical models of the last deglaciation.
Paleo-environment Publications
- Paleo-reconstructions in the paper Glacial Isostatic Adjustment of the Laurentian Great Lakes Basin: Using the Empirical Record of Strandline Deformation for Reconstruction of Early Holocene Paleo-Lakes and Discovery of a Hydrologically Closed Phase lead to the discovery of a long-lasting lowstand when lake levels stood many metres below the elevation of lake outlets. Possible causes for this lowstand include the predominance of dry air masses over the Great Lakes basin prior to the establishment of modern, moister air masses, a hypothesis that is highly significant in the context of future climate change.
For more information: Extreme Changes in Great Lakes Paleo-levels in the Early Holocene
- In the paper Late Quaternary Vegetation History of Northern North America Based on Pollen, Macrofossil, and Faunal Remains, the late glacial and Holocene history of biome change within glaciated North America is summarized. Unlike other recent biome reconstructions, these constructions incorporate fossil mammal data in conjunction with paleovegetation.
- A significant contribution to the late glacial and early Holocene dune and paleoclimatic history of central and western Canada is provided in the paper Relict Late Wisconsinan Dune Fields of the Northern Great Plains, Canada. The authors interpreted dune activity in tundra settings along the margins of the Laurentide and Cordilleran ice sheets between 16,000 and 9,000 years before present.
- In the paper Stable Isotope Records from Mount Logan, Eclipse Ice Cores and Nearby Jellybean Lake. Water Cycle of the North Pacific Over 2000 Years and Over Five Vertical Kilometres: Sudden Shifts and Tropical Connections, new insights into abrupt shifts in the water cycle of the North Pacific over the last 2 000 years are presented. A shift from predominantly zonal flow transport of water vapour to mixed (modern) flow in A.D. 1840 is interpreted as coinciding with the end of the Little Ice Age.
Study Data
Late quaternary eolian deposits of northern North America, age and extent: 126 maps of surficial geology and eolian deposits available from Geological Survey of Canada (Open File #6006)
Links
Reprints from the publications listed above are available from individual authors, or on-line at the links below. Please note that subscriptions may be required to view the articles.
Géographie physique et Quaternaire (GpQ), Volume 58
Géographie physique et Quaternaire (GpQ), Volume 59