Geological Features of the Earth

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Geological Features of the Earth

• Unit EQ How do natural processes affect
  geologic features?
• Diane Gioia
• Bells Crossing Elementary

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What are the geologic landforms on the continent?

• When you think of landforms, you might think of
  mountains or valleys. These are continental
  landforms, or landforms on the continents.
• Landforms are also found under the oceans water.
  These are called oceanic landforms.

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Plains

• Plains are large flat areas of land that are
  relatively low. A plain found in the ocean is
  called an abyssal plain. The Central United
  States has the Great Plains as shown below.

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Mountains and Hills

• A mountain has high elevations with steep sides
  and pointed tops. The top of the mountain is a
  peak, or summit.
• A hill is similar to a mountain but it has a
  lower elevation. It is usually rounded but not
  as high as a mountain.

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Valleys

• Valleys are low, narrow areas on Earths crust.
  On land, valleys are usually formed by erosion.
• Valleys in the ocean are called a rift zone, or
  rift valley. These are formed when the plate
  boundaries move apart from each other.

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Canyon and Trenches

• A canyon has steep, rocky walls and is usually
  formed by water erosion like the Grand Canyon.
• Ocean trenches have a much lower elevation than
  the surrounding area and is caused by one plate
  sliding under another plate.

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• A volcano is a mountain that opens downward to a
  pool of molten rock below the surface of the
  earth. When pressure builds up, eruptions occur.
  Gases and rock shoot up through the opening and
  spill over or fill the air with lava fragments.
  Eruptions can cause lateral blasts, lava flows,
  hot ash flows, mudslides, avalanches, falling ash
  and floods. Volcano eruptions have been known to
  knock down entire forests. An erupting volcano
  can trigger tsunamis, flashfloods, earthquakes,
  mudflows and rockfalls.

Mt. St. Helens Washington
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Seamounts

• Volcanic cone shaped peaks that dot the ocean
  floor are called seamounts. Most are found in
  the Pacific Ocean.
• Most seamounts began life as volcanoes formed
  over hot spots in the ocean floor

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Continental vs. Oceanic Landforms

• Canyon
• Valley
• Volcano
• Mountain range
• Low hills or plains

• Trench
• Rift
• Seamount
• Mid-ocean ridge
• Ocean basin and abyssal plains

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What are the landforms on the ocean floor?

• The amazing ocean floor is made up of three
  parts
• the continental shelf
• the continental slope
• the deep blue sea

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Continental Shelf

• The edges of the continents slope down from the
  shore into the ocean. The part of the continent
  located under the water is the continental shelf.
• In some places the shelf is fairly shallow and in
  other places it becomes very deep.

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• The steep slope where the continental shelf drops
  to the bottom of the ocean floor is called the
  continental slope.
• The depth of the water increases greatly here.

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Mid-Ocean Ridge

• On the bottom of the ocean, there is a central
  ridge, or mountain range, that divides the ocean
  floor into two parts. These underwater volcanic
  mountains are the mid-ocean ridge.

DID YOU KNOW? The Earths largest mountain range
is underwater.
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Trenches

• The many steep-sided canyons and deep, narrow
  valleys in the bottom of the ocean are trenches.
  Ocean trenches are the deepest part of the ocean
  basin and are deeper than any valley found on
  land.

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Did you Know?

• The Marianas Trench in the Pacific Ocean is the
  deepest trench in the world. It is nearly 7
  miles (ll kilometers) below sea level. Mount
  Everest is only 5.5 miles (9 kilometers) above
  sea level.

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• The deep ocean basin, which is about 2.5 to 3.5
  miles deep, covers 30 of Earth's surface and
  has features, such as abyssal plains, deep-sea
  trenches and seamounts.
• The abyssal plain is the flat, deep ocean floor.
  It is almost featureless because a thick layer of
  sediment covers the hills and valleys of the
  ocean floor below it.

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Quick Quiz

• The ocean is a big, flat featureless plain.
• True or False
• false
• The steep part where the continental shelf slopes
  down to the deepest part of the ocean is called
  the continental slope.
• True or False
• true

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• 3. What are the deepest parts of the ocean
  called?a. Deep-sea trenchesb. Abyssal
  plainsc. Continentsd. Seamounts
• Deep sea trenches
• 4. What is a seamount?
• a. A scientist who studies the ocean floorb.
  Deep-sea trenchc. A fancy seagulld. A volcano
  that formed over a hot spot on the ocean floor.
• D

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• How can we classify and illustrate natural
  processes as constructive or destructive?
• Constructive Processes that create landforms
• Destructive Processes that destroy landforms

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Natural Processes that can affect Earths oceans
and landforms include

• Weathering a term used to describe processes
  that break down rocks at or near the surface of
  the earth. Water is an important cause of
  weathering.
• Anything that causes rocks to wear down or break
  apart is a cause of weathering.
• Erosion the movement of sediments and soil by
  wind, water, and gravity

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• Deposition the dropping, or depositing, of
  sediments by water, wind, or ice. Deposition
  builds up new land on Earths surface, like a
  delta at the end of a river or the pile up of a
  sand dune in a desert. Shells on the beach are
  deposition by ocean waves.
• Landslides mass movements of land due to
  gravity. Landslides can cause buildings to fall,
  or power and gas lines to break. Landslides even
  occur on the continental slope in the ocean.

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• Volcanic Eruptions Volcanoes can change the
  Earths surface. When the magma erupts from the
  volcano, the top of the mountain can be changed.
  The lava and ash can destroy forests and bury
  fields. Eruptions can even change weather
  patterns.
• Earthquakes vibrations on the surface of the
  Earth caused by sudden movement in Earth, often
  along a fault line. Large earthquakes can cause
  landslides. Earthquakes under the ocean can
  cause huge waves, called tsunamis that destroy
  land and cause great damage on shore.
• Floods rapid erosion can take place and move
  soil and sediments away. When the flood recedes,
  new sediment is left behind and can build up rich
  soil deposits.

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What are examples of ways natural processes can
be both destructive and constructive?
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Think youve seen coastal erosion?

• Check out this quick clip!
• http//whyfiles.org/091beach/images/house.mov

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Optional Video Streaming
Weathering 658
Giant Waves 417
Erosion 554
Earthquake 316
Deposition 118
Volcanoes 441
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What am I? Riddle BookYou need to create a
riddle book from your continental landform terms.
You will create a book with a cover (your name
needs to be in the top right hand corner), and a
page for each term. Each page will have a riddle
(one for each term), with the answer on the back
of that page.
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Oceanic Landform Picto-Cards You will create
seven picto-cards, one for each oceanic landform
listed on your matrix. On one side of the card
you will draw a picture of the landform. On the
flip side you will write the term and its
definition, then your choice of an analogy or a
sentence.