~ Glaciers and Ice Ages ~
There are two kinds of glaciers:
1. Alpine Glaciers (left) and 2. Continental Ice Sheets (right)
Learn about Glaciers / Resource Guide / Image
Alpine (Mountain or Valley) Glaciers / Melting / Anatomy of a Glacier
Alpine Glacier (above) - Continental Ice Sheet (below)
Chasing Ice Calving Scene / Chasing Ice Film Trailer / "Before My Time" Theme Song
Continental Ice Sheet
Earth's Two Continental Ice Sheets:
Antarctica and Greenland
Antarctica (South Pole)
Antarctic Ice Sheet
1. Antarctic Ice Sheet = 90% of world's continental ice sheet volume
2. Greenland Ice Sheet = 10% of world's continental ice sheet volume
Greenland Ice Sheet
Note: Greenland should have been named Iceland, and Iceland should have been named Greenland.
~ Glacial Landforms ~
Anatomy of an Active Alpine Glacier
Anatomy of a Receding Continental Ice Sheet
Receding (melting) glaciers leave behind glacial deposits such as:
Eskers, Drumlins, Kettles, Striations, Terminal Moraine Till.
Glacial Esker Hill
FYI: Author's Ridge in Concord, MA is an Esker Hill.
FYI: Did you know that Cape Cod was created entirely by GLACIAL TILL material?
As a glacier recedes and melts, it dumps out sediment (till) at the sides and base, which is moraine.
Cape Cod: Glacial Terminal Morraine / History of Boston / Shawmut
Above: Glacial Striation Scratches (left) and Polished Rock (right)
Glacial Drumlin Hill / Drumlin Farm
You can determine the direction of the glacier's movement by the shape of the drumlin.
Kettle Hole Lakes by Satellite:
How Kettle Holes and Kettle Hole Lakes form:
Walden Pond is a Glacial Kettle Lake:
Walden Pond State Reservation / Glacial Kettle Hole Lakes
Visit (former) Glacier National Park in Montana
Above: Glacial "Milky Lake" with suspended "Glacial Flour" (finely-ground rock)
Rivers form a V-Shaped Valley / Glaciers form a U-Shaped Valley
Glacial Erratic Boulder (rounded and tumbled by the ice):
randomly dropped out the the melting glacial ice.
Glacial Erratic Boulders
Stone Walls in New England:
Rocky Soil due to Glacial Erratic Boulders
~ Learn about the Ice Ages ~
Ice Age Fun Facts:
1. >>> There have been five (5) major Ice Ages during Earth's history.
>>> The most extreme of them was an Ice Age nicknamed, "Snowball Earth."
2. >>> We are technically still in an Ice Age today since there are two (2) major continental ice sheets on Earth.
>>> The current ice age is called the Great Ice Age.
>>> The Great Ice Age started 2.6 million years ago.
>>> It's peak was 20,000 years ago, and the ice from that era is slowly melting away as temperatures rise.
>>> For the past 10,000 years, we have been in an "interglacial" period of that Ice Age.
3. >>> Today, Earth's two (2) continental ice sheets are located in:
( Antarctica and Greenland )
>>> Ninety percent (90%) of ice sheet mass is Antarctic, ten percent (10%) Greenlandic.
4. >>> Presently, ten percent (10%) of the land is covered by glaciers.
>>> During the peak of this Ice Age, thirty-two percent (32%) was covered by ice.
5. >>> Seventy percent (70%) of the Earth is covered with water, and thirty percent (30%) is land.
>>> Ninety-seven percent (97%) of Earth's water is salty, and only three percent (3%) is fresh water.
>>> Sixty-nine percent (69%) of the fresh water on Earth is in the form of glacial ice with thirty percent (30%) as groundwater and less than one percent (<1%) surface water.
If you took ALL the water on Earth, and turned it into a sphere,
then it would have a diameter of only 860 miles across! (Shown above)
Click here: Earth's Five Ice Ages / Snowball Earth
(650 million years ago)
The Current "Great Ice Age"
Maximum Extent of "Wisconsin Ice Sheet"
during the peak of the "Great Ice Age"
Extent of Ice Sheet in North America
kya (thousands of years ago)
The "Great Ice Age" started 2.6 million years ago, and continues at present.
The Great Ice Age peak was 20,000 years ago. (shown above)
The active "glacial" period ended about 11,700 years ago.
Since then, we have been in an "interglacial" period.
During the Ice Age Peak:
Europe, Asia, and North America was covered by an Ice Sheet.
BBC Ice Age / Great Ice Age Glaciation / Maps
Ice Age: The Movie / 2012 Ice Age Movie
Museum Tour / Useful Ice Age Resource Links / La Brea Tar Pits of California
The Pleistocene Epoch spanned from 2.6 million years ago to 11,700 years ago.
Early Man Hunted many Pleistocene Megafauna (Giant Mammals) to Extinction.
FYI: Dwarf Wooly Mammoths survived on an isolated island
as recently as 5,000 years ago, then finally went extinct.
Click here: Pleistocene Mammals / Pleistocene Epoch
Above: Giant Pleistocene Beaver (8 feet long)
Giant Ground Sloth
Ice Age / Mega-Fauna / Index / Mammals / Extinction / La Brea Tar Pit Photo Tour
Above: Irish Elk (Pleistocene)
Above and Below: Saber-Toothed Cat (Smilodon fatalis)
Above: Pleistocene Milodon (Giant Ground Sloth)
Above: Argentinian Teratorn (28 foot wing span) Largest Known Bird
Above: Horse Evolution during the Ice Age