Transcript Mod2/3-C Lake Ecology - Basins & Morphometry

LAKE ECOLOGY
Unit 1: Module 2/3 Part 3 – Basins and Morphometry
January 2004
Modules 2/3 overview
 Goal – Provide a practical introduction to
limnology
 Time required – Two weeks of lecture (6
lectures) and 2 laboratories
 Extensions – Additional material could be used
to expand to 3 weeks. We realize that there are
far more slides than can possibly be used in
two weeks and some topics are covered in
more depth than others. Teachers are expected
to view them all and use what best suits their
purposes.
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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Modules 2/3 outline
Introduction
Major groups of organisms; metabolism
Basins and morphometry
Spatial and temporal variability – basic
physical and chemical patchiness (habitats)
5. Major ions and nutrients
6. Management – eutrophication and water
quality
1.
2.
3.
4.
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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3. Lake basins & morphometry
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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Lake types and classifications
 Lakes are open bodies of slow moving water
not in contact with the ocean
 Lake origin and geology determine:
 Basin area, shape, depth
 Watershed size and mineral soils
 Basic water quality and sediment characteristics
Insert ~ 4 photos of various pond, lake, and reservoirs
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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Major Lake Types
 Major types:
 glacial
 tectonic
 volcanic
 reservoirs
 solution
 landslide
 oxbow
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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Glacial lake basins
 Most recent ~14,000
b.p.
 ice scour lakes
 morainal lakes
 ice block/kettle lakes
 Includes most of the
lakes in the Upper
Great Lakes and New
England region
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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Lots of beautiful glacial lake basins out there
 Castle Lake, CA: cirque lake
formed by glacier scour
leaving a terminal moraine at
the outflow and a lateral
moraine than separates a 5m
deep littoral plain from a 35
m deep bowl
 Typically have low watershed
to lake area ratio (Aw : A0)
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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Tectonic lake basins – Graben-Rift
 Faults and depressions
Lake Tahoe, CA-NV
created from crustal
movements
 The deepest lakes in
the world were formed
from parallel fault
blocks that sank to
create flat-bottomed
grabens (Tahoe, Baikal,
Tanganyika)
(tahoe.usgs.gov)
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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Tectonic Basins – Uplifted sea beds
 Slow uplifting of ancient sea beds to form
shallow depressions
L. Okeechobee, FL
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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More uplifted ancient seabeds
Images of uplifted sea beds
•Great Salt Lake
Developed by: R.Axler and C. Hagley
•L. Titicaca, Bolivia-Peru
Draft Updated: January 13 , 2004
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Volcanic – Caldera Lakes
 Crater Lake- 589 m deep
(Mt. Mazama exploded)
 Very low watershed to
lake area ratio (Aw : A0)
•http://geopubs.wr.usgs.gov/fact-sheet/fs092-02/
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Steep sides
Low nutrient soils
Unproductive
Extremely clear
•www.cs.uoregon.edu/.../oregon/large/
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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Other lake types
Reservoirs – What’s that dammed
lake for ?
 usually created for multiple uses
and so result in multiple conflicts
Solution lakes – formed by
the dissolution of limestone
deposits
USBR: http://www.hooverdam.usbr.gov/
 Are sinkholes in Florida
prime lakeshore real estate ?
 Areas with numerous
solution lakes are known as
“Karst topography”
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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And more lake types
Landslide formed
Oxbow lakes –
the river changed course
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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The WOW lakes
 Shagawa L., MN - glacial
 L. Minnetonka - glacial
 Medicine L., MN – glacial
 Independence, MN - glacial
 Ice L., MN - glacial
 Grindstone L., MN - glacial
 L. Onondaga, NY – morainal
 L. Washington, WA – fjord lake
 L. Mead, NV/AZ - reservoir
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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WOW Minnesota Lakes
Wow lake images
Ice Lake
Medicine
Independence
Developed by: R.Axler and C. Hagley
Shagawa
•Lake Independence
Draft Updated: January 13 , 2004
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Lake Minnetonka
 Formed by glacial melting
during the last Ice Age
 16 interconnected lakes; ~23
named bays and areas
Halsteds Bay
West Upper Basin
Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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WOW Lakes
Mead - Las Vegas Bay
Washington
Developed by: R.Axler and C. Hagley
Boulder Basin - Sentinel I.
Onondaga
Draft Updated: January 13 , 2004
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Developed by: R.Axler and C. Hagley
Draft Updated: January 13 , 2004
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