what do we do when the earth decides to change… so much to do…
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Chapter 2-3 Internal forces - will be due today MIRPL Assignment - coming this week Progress reports entered - missing assignment – do nows, class work, latitude and longitude
Is your ID on?
Current Events: World
More bodies from Japanese volcano eruption
- no lava flows at this time - more activity to follow
Protests in Hong Kong - prodemocracy movement - China cracking down on protests
Richter Scale
Way to measure strength of earthquakes
- we feel a 2.0 - more severe at 4.5 and above Strongest in Chile, 1960 - measured 9.5 Indonesia, 2004 - 9.1 magnitude - large Tsunami, killed
thousands
Tsunami
Caused by earthquakes - occur in the ocean Giant wave of water - can top 100 feet high - speeds up to 450 mph Creates total destruction - Indonesia, 225,000 killed - 1.2 million displaced
Volcanoes
3 types of volcanoes - Composite, Cone,
Shield Occur along plate boundaries Extremely
destructive Create new
landforms - island formation - land masses,
mountains
Weathering
Physical and chemical process that occurs over a long period of time
Mechanical Weathering- physical forces that break rock into smaller pieces- does not change rock the “stuff” in a rock, only makes it smaller in size, breaks into pieces
- ex. Ice forms in cracks of rocks and causes them to break
Weathering
Chemical Weathering- the “stuff” in a rock is changed chemically- creates a new composition- the “stuff”, minerals, react with water or air
- ex. Iron in rock rusts from air and water, rock changes and crumbles
Erosion
Occurs after weathering, mechanical process that moves materials- occurs by using wind, water, ice, and gravity- rock materials (sediment) is moved to another location
Question: How does “dirt” from Lancaster County end up in the Chesapeake Bay?
T-P-S: Questions to answer at your table
How does water erode the surface?
How is ice (glaciers) a powerful form of erosion?
Wind as a form of erosion, how?
Gravity as a form of erosion, how?
Water Erosion
Rivers and Streams (Type 1)- moves material downstream- stronger currents move more material
Abrasion- rock is ground by particles (sediment)- faster water equals more grinding
Dissolving- chemical breakdown of material in water
Water Erosion
Erodes both horizontally and vertically- rivers become wider and deeper
As the river slows…- particles drop out of the water- Delta formation at the end of a river
Beaches- increase and decrease- some lose 3ft per year
Wind Erosion
Similar to erosion by water- wind picks up material and moves it- can be abrasive – think about dirt blowing in the air
New land features- sand dunes
Loess- sediment deposits- very fertile soil
Glacial Erosion
Erosion by glaciers (ice)
As a glacier moves…- picks up material and transports it like a river- pieces left behind or deposited in new locations- glaciers move because of gravity
Glaciers cut grooves in rocks- grind rocks- leave behind various other particles and features
Soil formation
Weathering and erosion create soil- moved sediment becomes soil- amount of biological material called Humus
Soil Factors- Parent material – stuff the soil is made from- Relief – steep slopes produce less soil- Organisms – plants and critters (worms, bacteria)- Climate – affects soil types, cold v. hot- Time – amount of time to produce soil (long process)