Agenda: Thursday Opening Activity PPT and notes Bill Nye Presentation Marks Rock Cycle Quiz- MONDAY Physical Unit Test- Mon, April 22nd
Physical Geography thus far…. Layers of the Earth Continental Theory Plate Tectonics Volcanoes Earthquakes Rock Cycle and now….
Layers of the Earth 1) 2) 3) 4)
Continental Drift Who What When Why
Tectonic Processes Who What When HOW
Types of Tectonic Boundaries 1) 2) 3)
Volcanoes 3 ways of describing them? 3 TYPES Inside a volcano Hot Spots? Positives and Negatives of volcanoes
Earthquakes Hypocentre vs. Epicentre Richter Scale Where do they happen?
Rock Cycle
EROSION & GLACIERS
Looking at two things today: 1. Forces of Erosion 2. Glaciers/Glaciation
Forces of Erosion Weathering and erosion continually work to even out the Earth’s surface
WHAT IS EROSION? Erosion the movement of sediment or soil from one location to another by means of water, ice, and wind
WHAT IS WEATHERING? Weathering the breaking down of materials such as rocks and minerals by physical, chemical or biological processes
WHAT IS DEPOSITION? Deposition When particles carried by water, ice, or wind are deposited (dropped) in another location
CAUSES OF EROSION/WEATHERING
EXAMPLES OF EROSION
EXAMPLES OF EROSION
Most of the landscape in Canada and the Northern United States has been shaped by glaciers. Copyright © 2010 Ryan P. Murphy
Glaciers
Backgrounder: Glaciers In the polar regions and on high mountains, cold temperatures stop snow from melting. As more snow falls on top, it builds up in deep layers that, over centuries, are compressed into solid ice
Backgrounder: Glaciers This mass of ice tends to creep downhill as glaciers, and where these reach the sea the ice breaks away to form floating icebergs
WHAT IS A GLACIER? Glacier: A mass of snow and ice that moves downhill. Glaciers can be found on: Mountains Continents (Greenland, Antarctica)
Video Link! Going inside a Glacier http://www.youtube.com/watch?v=cIBFAke90SI
Two Types of Glaciers Alpine Glaciers: long, slow-moving, rivers of ice found in areas of high elevation (mountain areas). Continental Glacier (ICE SHEETS): a very old, thick mass of ice covering almost an entire land mass
Alpine Glacier
Continental Glacier
Glaciers form when more snow and ice accumulate than melt.
WHAT DO GLACIERS DO? Glaciers do 2 main things to the land: They break the Earth’s surface into smaller pieces They carry the smaller pieces to new places and drop them off when they melt (turn back into water).
HOW ARE GLACIERS MADE?
WHAT IS THE ZONE OF ACCUMULATION? The Zone of Accumulation is the part of the glacier where the snow builds up (collects) If there is more snow collecting than snow melting, the glacier grows
WHAT IS THE ZONE OF ABLATION? The Zone of Ablation is where melting occurs (happens). If there is more melting than snow falling, the glacier gets smaller
Let’s have a look at a Glacier Place where snow collects Place where snow melts
A typical Glacial moves either forward (if it gets bigger) or backwards (if it gets smaller)
As long as Accumulation = Ablation, the Glacier does not move forward
If accumulation is more than ablation, the Glacier moves forward
If ablation happens more than accumulation, the Glacier gets smaller
Eventually, material trapped in the ice reaches the front of the glacier and is deposited (dropped off)
Agenda Fri: Opening Activity Quiz Rock Cycle- this MON Test- Mon 22nd Finish PPT from yesterday Walking with Beasts
EVIDENCE OF GLACIERS Abrasion is the wearing down of rock by the grinding effect of rock fragments frozen into the bottom of glaciers. Three examples of abrasion are: Polish Striations Gouges
POLISH
STRIATIONS
GOUGES
EVIDENCE OF GLACIERS Deposition is when rock and soil picked up and moved by a glacier is dropped off in a new area to create new landscapes. Till (material that is not sorted and not in layers) Outwash (deposits made by streams after glaciers melt) Erratics (boulder-sized rock dumped by a glacier)
GLACIAL TILL
OUTWASH
ERRATIC
Erratic: How did this rock get like this?
Glacial Movement Answer: Our next area of Focus. Copyright © 2010 Ryan P. Murphy
Answer: Our next area of Focus. Copyright © 2010 Ryan P. Murphy
Slow Melting Answer: Our next area of Focus. Copyright © 2010 Ryan P. Murphy
Slow Melting Answer: Our next area of Focus. Copyright © 2010 Ryan P. Murphy
Answer: Our next area of Focus. Copyright © 2010 Ryan P. Murphy
Answer: Our next area of Focus. Copyright © 2010 Ryan P. Murphy
Why is this a picture of this classroom 35,000 years ago? Copyright © 2010 Ryan P. Murphy
Answer: We would have been buried under a mile of ice in complete darkness. Copyright © 2010 Ryan P. Murphy
Our city may have looked like this 35,000 years ago….why?
Ice Ages Ice Ages are periods when the Earth’s climate cools enough to allow large continental glaciers to flow from the polar regions to regions farther south. There have been at least four ice ages during the past million years.
Ice Ages The last ice age was called "The Great Ice Age", and it occurred 11,000 years ago. During the "Great Ice Age” over one third (1/3) of the earth was covered in ice
Cool Mammals! During the last Ice Age, there were many large, interesting mammals, like the saber-toothed cats, giant ground sloths, mastodons, and mammoths. These animals have long since gone extinct and are known mostly from fossils, from frozen, mummified carcasses, and even from ancient cave drawings.
Giant Ground Sloth
Giant Ground Sloth
Giant Armadillo
Giant Armadillo Extinct
Dire Wolf
Dire Wolf Extinct
Short Faced Bear
Short Faced Bear Extinct
Saber-toothed Cats
Saber-toothed Cats Extinct
Giant Beaver
Giant Beaver Extinct
Terror Birds Extinct
Present Day Bird Species Size Comparison
Present Day Bird Species Size Comparison
Present Day Bird Species Size Comparison
“Imagine how cool it would be to have these Terror Birds running around today.”
Video! Glacier Breaking Apart. Dangerous http://www.youtube.com/watch?v=rfv94J5eDeg