Supercontinent - Pangea . . .
(zoom in to view the names of the
geologic eras)
Alfred Wegner
Supercontinent - Pangea . . .
Pangea
Gondwanaland
Laurasia
Geologic Time
Milankovitch Cycles
(~ 100,000 years)
Milankovitch Cycles
(~ 100,000 years)
Milutin Milankovitch
(1879-1958)
Factors affecting
Earth’s Climate
1. Milankovich Cycles
(~100,000 years)
2. Pacific Decadal Oscillation
(~10 – 15 years)
3. El Nino/La Nina Cycles (annual cycles*)
Time Scale: The Cenozoic Era
“Recent Life”
• Pleistocene Epoch
– Ice ages (WIKN)
– Humans appear
– 1.8 my to 10,000 yr
http://www.museum.state.il.us/exhibits/ice_ages/images/loopglac.gif
Continental Glaciers . . . . .
Stages
Wisconsin
(most recent)
What is a
“nunatak”?
Illinoian
Kansan
Nebraskan
(oldest)
Human Migration
National
Genographic
Project
Human Migration
Source: www.utexas.edu/features/2007/ancestry/
Continental Glaciers . . . . .
Question: What type of
vegetation covered the
landscape immediately south of
the continental glaciers?
Glaciers, Biotic Exchange,
and Vegetation Patterns
Vegetation Patterns
during Glacial Periods
North American Glaciers . . . . .
Note the
names
and
locations
of the
refugium
Glacial Lake Missoula
Glacial Lake Missoula
The name Missoula is derived from a Flathead (Salish) term
meaning “cold, chilling waters”.
Continental Glaciers . . . . .
How did the continental
glaciers affect the Willamette
Valley?
Glacial Lake Missoula
Glacial Lake Missoula
A Sudden Onslaught of Water
The Dalles, Oregon ~ 1,000 feet
Question.. . . . . . . . .
Question: As the glaciers
formed, they locked up water,
how much lower were sea
levels then?
Astoria Trench
Pacific Salmon Species
Genus Oncorhynchus – “hooknose”
Pink Salmon (O. gorbuscha)
Steelhead Trout (O. mykiss)
Chum Salmon (O. keta)
Sea-run Cutthroat Trout (O. clarkii)
Sockeye Salmon (O. nerka)
Coho Salmon (O. kisutch)
Chinook Salmon (O. tshawytscha)
Glacial Lake Missoula
Glacial Erratics
Lake Bonneville
The lake was named after the
early explorer, B.L. Bonneville.
It was formed about 50,000 years
ago and had receded to the
current level of the Great Salt
Lake by about 10,000 years ago.
It was about 560 km (about 350
mi) long and 240 km (150 mi)
wide, had a maximum depth of
more than 305 m (1000 ft), and
was more than 1525 m (5000 ft)
above sea level.
Megafaunal Extinctions
Megafaunal Extinctions
Megafaunal Extinctions
The stag-moose
(scientific name Cervalces scotti)
Shasta ground sloth
Nothrotheriops shastensis
Megafaunal Extinctions
Ancient Bison
Bison Antiquus
Dwarf Pronghorn
Capromeryx minor
Extinct Camel
Camelops hesternus
Megafaunal Extinctions
Columbian Mammoth
Mammuthus columbi
American Mastodon
Mammut americanum
Megafaunal Extinctions
Sabertoothed Cat
Smilodon fatalis
American Lion
Panthera atrox
Megafaunal Extinctions
Short-faced Bear
Arctodus simus
Dire Wolf
Canis dirus
The Misnamed Extinct
“Irish Elk”
~ 4 meters
Source: http://www.ucmp.berkeley.edu/mammal/artio/irishelk.html
Holocene Ecology
Anthropocene?
1.
2.
3.
Vegetation Patterns
Ecological Communities
Species and Populations