Transcript Mr. Burton 2.3 Notes

Mr. Burton 2.3 Notes
Please Grab:
1. Your folder.
2. Writing Utensil.
3. Answer the following question: How does
the surface of the earth move?
Earth’s surface has many different
landforms
 Landforms, or shapes on the planet’s surface, make
up the landscapes that surround us.
 Earth’s surface is covered with landforms of many
different shapes and sizes.
 Mountains, land that rises higher than 2,000 feet
 Valleys, areas of low land located between mountains
or hills
 Plains, stretches of mostly flat land
 Islands, areas of land completely surrounded by
water
 Peninsulas, land surrounded by water on three sides
Below the earth’s surface
 The planet’s continents, or large landmasses, are
part of Earth’s crust—the solid outer layer of the
planet.
 Theory of plate tectonics suggests that Earth’s
surface is divided into a dozen or so slow-moving
plates, or pieces of Earth’s crust.
 The idea that continents have traveled great distances
over millions of years is known as continental drift.
 Theory, developed by Alfred Wegener, states that the
continents were once united in a single supercontinent
and over time, slowly separated and moved to their
present positions.
 As plates collide, separate, and slide, they shape
Earth’s landforms
Collide, Separate, and Slide
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Two ocean plates: one pushes under the other, creating ocean
trenches, or deep valleys in ocean floor
Ocean and continental plate: ocean plate drops beneath
continental plate, forcing land above to crumple and form
mountain range
Two continental plates:
land pushes up to form mountains
As plates move apart, gaps between plates allow magma to rise
to Earth’s crust.
Lava, magma that reaches the Earth’s surface, emerges from
the gap.
As lava cools, it builds a mid-ocean range, or underwater
mountain, that can rise above the surface of the ocean to form
islands.
As plates pass by each other, they sometimes grind together,
producing earthquakes, sudden, violent movements of Earth’s
crust.
Earthquakes often take place along faults, or breaks in Earth’s
crust where movement occurs.
The region around the Pacific plate, called the Ring of Fire, is
home to most of the world’s earthquakes and volcanoes.
Forces on the planet can alter the
earth’s surface.
 Weather, water, and other forces change Earth’s
landforms by wearing them away or reshaping them.
 Weathering is the process by which rock is broken
down into smaller pieces called sediment.
 Heating and cooling can cause rocks to crack.
 Expansion of water as it freezes can cause cracks to
expand.
 Roots of trees can pry rocks apart.
 Erosion is the movement of sediment from one
location to another.
 Can wear away or build up landforms
Different types of erosion: Wind,
Glacial, and Water
 Winds lift sediment into air and carry it across great
distances .
 On beaches and in deserts, deposits can form dunes.
 Blowing sand can wear down rock.
 Glaciers, or large, slow-moving sheets of ice, erode
the land by carving valleys and mountain peaks.
 Crush rock into sediment and move it great distances
 Waves and flowing water can cut through rock, carry
sediment, and deposit sediment in new locations.
 Floodplains are created when rivers flood their banks
and deposit sediment.
 Sediment carried by a river all the way to the sea
creates a delta.
Exit Slip:
 What are the three types of erosion
that we have?