Western Canadian Association of Geographers Western Division Meeting 2009

323 views

Published on

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
323
On SlideShare
0
From Embeds
0
Number of Embeds
5
Actions
Shares
0
Downloads
2
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Western Canadian Association of Geographers Western Division Meeting 2009

  1. 1. Dendrochronologic record for mid-late Holocene glacial activity in Manatee Valley, Upper Lillooet Provincial Park, southern Coast Mountains, BC Lindsey E. Koehler and Dan J. Smith University of Victoria Tree Ring Laboratory Department of Geography University of Victoria Victoria, BC
  2. 2. Outline <ul><li>Introduction to the research context </li></ul><ul><li>Study Area </li></ul><ul><li>Methods </li></ul><ul><li>Results </li></ul><ul><li>Discussion </li></ul><ul><li>Suggestions for future research </li></ul>
  3. 3. Historical Context for Glaciological Research in the B.C. Coast Mountains <ul><li>1930’s </li></ul><ul><ul><li>Early photographic records of glacier extents </li></ul></ul><ul><li>1940’s </li></ul><ul><ul><li>Post-WWII aerial photography </li></ul></ul><ul><li>1950’s </li></ul><ul><ul><li>Early applications of dendroglaciology to Little Ice Age moraines (Mathews, 1951; Brink, 1959) </li></ul></ul><ul><li>1960’s </li></ul><ul><ul><li>Radiometric dating applied to dendroglaciologic samples </li></ul></ul><ul><ul><li>Beginning of glacier mass balance monitoring at Place Glacier </li></ul></ul><ul><li>1980’s </li></ul><ul><ul><li>First detailed study of Holocene glacial activity (Ryder and Thomson, 1986) </li></ul></ul><ul><li>1990’s </li></ul><ul><ul><li>Continued work in the Coast Mountains </li></ul></ul><ul><li>2000’s </li></ul><ul><ul><ul><li>Detailed glacial reconstructions for entire Holocene </li></ul></ul></ul><ul><ul><ul><li>Expanding network of glacial chronologies </li></ul></ul></ul>
  4. 4. Study Area <ul><li>Geologic Setting </li></ul><ul><ul><ul><ul><ul><li>Coast Mountain Granitic Complex </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Quaternary volcanics </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Pleistocene glaciation </li></ul></ul></ul></ul></ul><ul><li>Biogeoclimatic Zones </li></ul><ul><ul><ul><ul><ul><li>ESSF </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>AT </li></ul></ul></ul></ul></ul>
  5. 5. Manatee Valley
  6. 6. Research Methods I <ul><li>Dendroglaciology </li></ul><ul><ul><li>Subfossil wood </li></ul></ul><ul><ul><ul><li>Detrital </li></ul></ul></ul><ul><ul><ul><li>In-situ </li></ul></ul></ul><ul><ul><li>First Colonizers </li></ul></ul><ul><ul><ul><li>Moraine crests </li></ul></ul></ul><ul><ul><ul><li>Distal slopes </li></ul></ul></ul><ul><ul><li>Living Trees </li></ul></ul><ul><ul><ul><li>Lateral margins </li></ul></ul></ul><ul><ul><ul><li>Tree islands </li></ul></ul></ul>
  7. 7. Research Methods II <ul><li>Lichenometry </li></ul><ul><ul><li>Assumptions </li></ul></ul><ul><ul><ul><li>Thalli expand at a constant rate </li></ul></ul></ul><ul><ul><ul><li>Largest thallus on surface is the first colonizer </li></ul></ul></ul><ul><ul><ul><li>Have surfaces of known age </li></ul></ul></ul><ul><ul><li>Temporal Range </li></ul></ul><ul><ul><li>Uncertainties </li></ul></ul><ul><ul><ul><li>Ecesis interval </li></ul></ul></ul><ul><ul><ul><li>Disturbance of the geomorphic surface </li></ul></ul></ul><ul><ul><ul><li>Microclimatic factors </li></ul></ul></ul><ul><ul><ul><li>Life history of lichen species </li></ul></ul></ul>
  8. 8. Results Overview <ul><li>Mid-Holocene Glacial Events </li></ul><ul><ul><li>4270±60 14 C years BP </li></ul></ul><ul><ul><li>3500±60 14 C years BP </li></ul></ul><ul><ul><li>3430±60 14 C years BP </li></ul></ul><ul><ul><li>2350±70 14 C years BP </li></ul></ul><ul><li>5-6 Little Ice Age moraine-building episodes </li></ul><ul><ul><li>Late-14 th Century </li></ul></ul><ul><ul><li>Continuous record from 18 th -20 th centuries </li></ul></ul>
  9. 9. Site 1 : Orca Glacier Snout
  10. 10. Site 2 : Manatee Glacier Lateral Margin
  11. 11. Site 3 : Orca/Beluga Glacier Forefield
  12. 12. Site 4 : Manatee Glacier Forefield
  13. 13. Site 5 : Orca/Beluga Lateral Moraine
  14. 14. Little Ice Age Moraines
  15. 15. Lichenometry at Manatee Valley
  16. 16. Lichenometric Dates for Moraine Stabilization
  17. 17. Moraine Dates vs. Tree-Ring-Widths
  18. 18. Discussion: Holocene Advances in Manatee Valley <ul><li>Mid-Holocene </li></ul><ul><ul><li>4200 14 C years BP event </li></ul></ul><ul><ul><li>‘ Early Tiedemann’ Advance </li></ul></ul><ul><ul><li>‘ Late Tiedemann’ Advance </li></ul></ul><ul><li>Little Ice Age </li></ul><ul><ul><li>1390’s </li></ul></ul><ul><ul><li>Mid-1550’s </li></ul></ul><ul><ul><li>Late-1600’s-early-1700’s </li></ul></ul><ul><ul><li>Early-1800’s </li></ul></ul><ul><ul><li>Late-1800’s </li></ul></ul><ul><ul><li>Early-1900’s </li></ul></ul>
  19. 19. Suggestions for Future Research <ul><li>Lichenometry </li></ul><ul><ul><li>More control surfaces from the southern Coast Mountains </li></ul></ul><ul><li>Dendroglaciology </li></ul><ul><ul><li>Tree-ring chronology development </li></ul></ul><ul><ul><li>Continued collection of subfossil wood as ice front recede </li></ul></ul><ul><ul><li>Mass Balance reconstructions </li></ul></ul>
  20. 20. Acknowledgements

×