FULL EPISODE
Lesson 19
Glaciation -
Understanding The Earth
Planet of Man
Series --
Trail of the
Ice Age Blues (30minutes)
Host;
Tuzo Wilson
Part 1 Planet of Man -- Trail of the Ice Age Blues 19-Part1
•
North American ice age
•
Images of different glacial topography
•
Greenland Ice sheet -- advance movement 60 feet a day.
•Images of an ice sheet breaking off into the sea.
•Greenland icebergs
Part 2 Planet of Man -- Trail of the Ice Age Blues 19-Part2
•
Movement of ice sheets
•Interesting graphics showing the movement of the
Laurentide ice sheet in
Canada and northern
United States
•Time lapse photography showing till movement.
•Deposits of glacial sheets.
•
Terminal moraines formed of till, knobby hills and depressions.
•Agricultural by-products from glacial movements
Part 3 Planet of Man -- Trail of the Ice Age Blues 19-Part3
•Outwash plains
•Kettles
•Spillways
•Kames - Kame
Terraces sources of sand and gravel
•Eskers valuable sources of sand and gravel
•Silty lake plains, clay plains
•Varved clays
•
Reflections of glaciation on people's lives
Glaciation -- Understanding the
Earth (30minutes)
Host; Dr.
David Pearson.
Part 4 Glaciation -- Understanding the Earth 19-Part4
•
Consequences; melting of the ice or advancing of the ice
•Causes of ice ages
•What do we know about climatic changes?
Good historically
•400ad 1200 AD mild weather voyages of the
Vikings
•1200 and 1400 cooling voyages more difficult for the Vikings
•1400 and 1550 warming
•1550 and 1850 'little ice age'
•At one
point in the little ice age
Eskimos (
Inuit) at one point could walk by foot over the glaciers to
Scotland from the north.
•
Right now there is a 'cooling down'
•
We are in a ice retreat.
•The last ice age formed about 2.5 million and retreat/advanced about 4 times
•
Frequency of ice ages
•
Elliott lake
Ontario, Ice age deposits left in the pre
Cambrian era
•
Glaciations in Permian, Palaeozoic no glaciation evidence has been found with our present glaciation of
200 million.
•Theories of short term climate effects on the earth
Part 5 Glaciation -- Understanding the Earth 19-Part5
•Theories of short term climate effects on the earth
•Accountablility in glaciation -- long-term and short-term changes in the climate of the earth
... advance and retreats
•Short-term changes in the climate of the earth
oPosition of the earth as it goes around the sun -
Tilt of the earth's axis "wobble of the earth
oAxis -- angle of the axis of rotation, presently @ 23.5 degrees
oEarth rotates around the sun in a eccentric orbit and every 92,
000 years moreover, the long axis becomes the short axis and the short axis becomes the long axis, every
108,000 years.
oMilankovitch cycles
Part 6 Glaciation -- Understanding the Earth 19-Part6
•Short-term changes in the climate of the earth
oPosition of the earth as it goes around the sun - Tilt of the earth's axis "wobble of the earth
oAxis -- angle of the axis of rotation, presently @ 23.5 degrees
oEarth rotates around the sun in a eccentric orbit and every 92,000 years moreover, the long axis becomes the short axis and the short axis becomes the long axis, every 108,000 years.
oMilankovitch cycles
•Long-term changes
oAntarctica covered by 2mies of ice, small shells coiled and age of sediment 16 million was the start of the
Antarctica ice age.
oAustralia moved away from Antarctica
oGreenland -- more than a mile thick of ice.
o
•Long-term changes
oArctic ocean -- Why did we get we get (4) periods of glaciation in the last 2 million years? The arctic ocean was open or rather melted.
oDistribution of ocean currents key to glaciation.
oWhy did the glaciers retreat?
oEffects of the last glaciation? -- mammoths
oAntarctica -- growing knowledge
o1911
Captain Scott's south pole expedition.
o20,000 years ago Ontario was covered by a mile thick of ice
- published: 25 Jun 2014
- views: 1338