Transcript Glaciers (2)

Two Different Types of Glacial Landforms:
1) Erosional; 2) Depositional
Types of Glacial Deposits:
1) Till – Left directly by the ice. Unsorted and
unstratified.
1) Stratified Drift – Left by glacial meltwater.
Usually sorted and layered.
TILL
STRATIFIED DRIFT
What sport does this topography remind you of?
Golf – invented in the glaciated landscape of Scotland!
1) Deposits Made of Till: Moraines
1) Deposits Made of Till: Drumlins
1) Deposits Made of Till: Drumlins
Deposits Left By Meltwater
OUTWASH
Kettles
ESKERS
Glaciers and Climate Change
Winter Landscape by Peter Brueghel, 1601
The Little Ice Age in Holland
The Pleistocene Epoch: 1.8 million to 10,000 years ago
A Much Different World
Earth’s Climate Cycles
Earth’s Climate Cycles
1) Glaciers are sensitive to climate changes and respond
by advancing and retreating.
2) Glaciers provide information about past climate.
a) Glacial deposits are evidence of a colder, past
climate (Till in Dayton is an excellent example).
b) Glacial ice contains air bubbles filled with the
ancient atmosphere. We can study past climate by
analyzing the composition of the ice bubble gases.
3) Glaciers influence climate change! Albedo is the
reflectivity of the Earth’s surface. More glacial ice
increases albedo and reflects solar energy back into
space. So, more ice reinforces cold climate.
The Geological History of Dayton, Ohio
40 thousand year old glacial till
Unconformity
450 Million year old limestones
The Geological History of Dayton, Ohio
Fig. 11.6b
Environments?