WHAT DO WE DO WHEN THE EARTH DECIDES TO CHANGE… So Much to do…..

Do Now- Write 5 Lines Can external changes on the earth affect human advancement? Explain your answer.

Information  Chapter external forces shaping the earth  MIRPL Assignment - coming this week  Progress reports finalized Is your ID on?

Current Events: World  ISIS attacks Iraqi military - check points and patrols - Iraqi army appears weak  Protests in Hong Kong - growing movement - China attempting to stop the protests

Do Now- Write 5 Lines Can external changes on the earth affect human advancement? Explain your answer.

T-P-S:

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)

TOTD In what ways does erosion affect the lives of humans? What are the three types of eroding action by water?