Transcript what happened here?

Warm Up
Review weathering and erosions as well as
the different types of each!
http://www.youtube.com/watch?v=lyysL02ZvQ8
WHAT HAPPENED HERE?
Today we’re going to be investigative
environmentalists working to find out
what happened to the land.
This calls for an expert!
• We are about to explore some mysterious
land changes, and I need your help
determining what happened.
• We need three groups of experts: one for
Erosion by Gravity, one for Erosion by Wind,
and one for Erosion by Glaciers.
• In your groups, use your text book to review
and record 5 key facts about your expertise.
Pick some key vocabulary words to record
as well.
– Work together, I need all the help I can get!
Share your knowledge
Elect a speaker from your group of experts. Share
your facts with the class. Let’s briefly discuss each
of the categories of erosion before we begin our
investigation. Let’s uncover the truth!
Erosion by GRAVITY
•Mass Movement: any type of erosion that happens as gravity moves
material down-slope. This happens either very slowly or very rapidly
(often by catastrophic event).
•SLUMP: when a mass of material slips down along a curved
surface. This occurs when a slope becomes too steep to support
the sediment above it. Rock and soil slips downward.
•CREEP: when sediments slows shift their position downhill.
Common in areas of frequent freezing and thawing.
•ROCK FALLS: occurs when blocks of rock break loose from a
steep slope tumble through the air. As they crash into other
rocks, more sediment breaks loose and tumbles down
•MUDFLOWS: usually occurs in areas with thick layers of loose
sediment, heavy rains causes it to turn thick and pasty while
gravity causes it to slip down a slope.
Erosion by GLACIERS
•A large mass of ice and snow moving on land under its own weight is a
glacier. Glaciers are agents of erosion.
•Plucking: when water fills the cracks in a rock but then freezes, it
can lift out pieces of the rock in the ice.
•Scouring: as a glacier moves, hard rock can be dragged along,
making striations and scarring rock.
What is a MORAINE DEPOSIT?
What is an OUTWASH DEPOSIT?
What is an ESKER?
Continental Glaciers: huge masses of ice, snow, and fragments where ice
and snow are thick and abundant.
Valley Glaciers: can occur where temperatures are warmer, these grow
slowly and creep along, typically on mountain tops.
Erosion by WIND
Deflation: when wind erodes by deflation, it blows across loose
sediment, removing small particles such as silt, sand, and clay.
Abrasion: when windblown material strikes rock, the surface of that
rock gets scraped and worn away over time.
*these two occur most commonly in deserts, beaches, and plowed fields.
Sandstorms: forceful winds cause more and more grains to rise into the
air and a low cloud of sandy particles can form.
Duststorms: when soil dries out it can be eroded by wind. This soil is
mostly clay or silt sized particles that are moved high into the air.
KEY VOCAB: Loess, dune, moving dune
Are we ready to use scientific
thought to infer what happened?
Case #2130
Location: Nachterstedt,
Germany, Saturday, July
18, 2009.
What evidence can we
gather from these photos?
What caused this damage?
Case #6210
Located in Montana
What are some features
we can identify before we
decide what caused these
formations?
Case #42j3
Located near the coast
What are some observations
we can make to determine
what happened here?
Case #k810
located east of Valdez Alaska.
What is the name of what we
see? What caused it?
Case #50073
These deposits were found near the
Yellow River in China. Notice that they
are fine grained and unlayered!
What is the name of this deposit? What
was the mechanism that caused this?
Case #7310
Location: Southern Egypt
What is this a picture of?
What caused these
sediments to pile up here?
What direction did the
movement occur? How
can we tell?
Case #198
We were informed that these results formed
very slowly.
What force is causing these deformations?
What is the name of the type of erosion
happening here?